diff --git a/content/treestyletab/treestyletab.js b/content/treestyletab/treestyletab.js
index 8ce920fa..fe05f761 100644
--- a/content/treestyletab/treestyletab.js
+++ b/content/treestyletab/treestyletab.js
@@ -343,6 +343,10 @@ var TreeStyleTabService = {
  
 	updateTabDNDObserver : function TSTService_updateTabDNDObserver(aObserver) 
 	{
+		if (aObserver.tabContainer &&
+			aObserver.tabContainer.tabbrowser == aObserver)
+			aObserver = aObserver.tabContainer;
+
 		if ('_onDragStart' in aObserver) { // Firefox 3.5 or later
 			eval('aObserver._onDragStart = '+
 				aObserver._onDragStart.toSource().replace(
@@ -355,7 +359,7 @@ var TreeStyleTabService = {
 				)
 			);
 		}
-		else { // Firefox 3.0.x
+		else if ('onDragStart' in aObserver) { // Firefox 3.0.x
 			eval('aObserver.onDragStart = '+
 				aObserver.onDragStart.toSource().replace( // native
 					'aEvent.target.localName == "tab"',
@@ -372,122 +376,130 @@ var TreeStyleTabService = {
 		var canDropFunctionName = '_setEffectAllowedForDataTransfer' in aObserver ?
 				'_setEffectAllowedForDataTransfer' : // Firefox 3.5 or later
 				'canDrop' ; // Firefox 3.0.x
-		eval('aObserver.'+canDropFunctionName+' = '+
-			aObserver[canDropFunctionName].toSource().replace(
-				'{',
-				'{ var TSTTabBrowser = this;'
-			).replace(
-				/\.screenX/g, '[TreeStyleTabService.getTabBrowserFromChild(TSTTabBrowser).treeStyleTab.positionProp]'
-			).replace(
-				/\.width/g, '[TreeStyleTabService.getTabBrowserFromChild(TSTTabBrowser).treeStyleTab.sizeProp]'
-			).replace(
-				/(return (?:true|dt.effectAllowed = "copyMove");)/,
-				<![CDATA[
-					if (!this.treeStyleTab.checkCanTabDrop(aEvent, this)) {
-						return TST_DRAGDROP_DISALLOW_RETRUN_VALUE;
-					}
-					$1
-				]]>
-			).replace(
-				/TST_DRAGDROP_DISALLOW_RETRUN_VALUE/g,
-				(canDropFunctionName == 'canDrop' ?
-					'false' :
-					'dt.effectAllowed = "none"'
+		if (canDropFunctionName in aObserver) {
+			eval('aObserver.'+canDropFunctionName+' = '+
+				aObserver[canDropFunctionName].toSource().replace(
+					'{',
+					'{ var TSTTabBrowser = this;'
+				).replace(
+					/\.screenX/g, '[TreeStyleTabService.getTabBrowserFromChild(TSTTabBrowser).treeStyleTab.positionProp]'
+				).replace(
+					/\.width/g, '[TreeStyleTabService.getTabBrowserFromChild(TSTTabBrowser).treeStyleTab.sizeProp]'
+				).replace(
+					/(return (?:true|dt.effectAllowed = "copyMove");)/,
+					<![CDATA[
+						if (!this.treeStyleTab.checkCanTabDrop(aEvent, this)) {
+							return TST_DRAGDROP_DISALLOW_RETRUN_VALUE;
+						}
+						$1
+					]]>
+				).replace(
+					/TST_DRAGDROP_DISALLOW_RETRUN_VALUE/g,
+					(canDropFunctionName == 'canDrop' ?
+						'false' :
+						'dt.effectAllowed = "none"'
+					)
 				)
-			)
-		);
+			);
+		}
 
 		var dragOverFunctionName = '_onDragOver' in aObserver ?
 				'_onDragOver' : // Firefox 3.5 or later
 				'onDragOver' ; // Firefox 3.0.x
-		eval('aObserver.'+dragOverFunctionName+' = '+
-			aObserver[dragOverFunctionName].toSource().replace(
-				'{',
-				<![CDATA[
-					{
-						if (this.treeStyleTab.processTabDragOverEvent(aEvent, this)) {
-							return;
-						}
-				]]>
-			)
-		);
+		if (dragOverFunctionName in aObserver) {
+			eval('aObserver.'+dragOverFunctionName+' = '+
+				aObserver[dragOverFunctionName].toSource().replace(
+					'{',
+					<![CDATA[
+						{
+							if (this.treeStyleTab.processTabDragOverEvent(aEvent, this)) {
+								return;
+							}
+					]]>
+				)
+			);
+		}
 
 		var dragExitFunctionName = '_onDragLeave' in aObserver ?
 				'_onDragLeave' : // Firefox 3.5 or later
 				'onDragExit' ; // Firefox 3.0.x
-		eval('aObserver.'+dragExitFunctionName+' = '+
-			aObserver[dragExitFunctionName].toSource().replace(
-				/(this.mTabDropIndicatorBar\.[^;]+;)/,
-				'$1; this.treeStyleTab.clearDropPosition();'
-			)
-		);
+		if (dragExitFunctionName in aObserver) {
+			eval('aObserver.'+dragExitFunctionName+' = '+
+				aObserver[dragExitFunctionName].toSource().replace(
+					/(this.mTabDropIndicatorBar\.[^;]+;)/,
+					'$1; this.treeStyleTab.clearDropPosition();'
+				)
+			);
+		}
 
 		var dropFunctionName = '_onDrop' in aObserver ?
 				'_onDrop' : // Firefox 3.5 or later
 				'onDrop' ; // Firefox 3.0.x
-		eval('aObserver.'+dropFunctionName+' = '+
-			aObserver[dropFunctionName].toSource().replace(
-				'{',
-				<![CDATA[
-					{
-						var TSTTabBrowser = this;
-						TSTTabBrowser.treeStyleTab.clearDropPosition();
-						var dropActionInfo = TSTTabBrowser.treeStyleTab.getDropAction(aEvent, TST_DRAGSESSION);
-				]]>
-			).replace( // Firefox 3.0.x, 3.5 or later
-				/(if \((accelKeyPressed|isCopy|dropEffect == "copy")\) {)/,
-				<![CDATA[
-					if (TSTTabBrowser.treeStyleTab.performDrop(dropActionInfo, draggedTab))
+		if (dropFunctionName in aObserver) {
+			eval('aObserver.'+dropFunctionName+' = '+
+				aObserver[dropFunctionName].toSource().replace(
+					'{',
+					<![CDATA[
+						{
+							var TSTTabBrowser = this;
+							TSTTabBrowser.treeStyleTab.clearDropPosition();
+							var dropActionInfo = TSTTabBrowser.treeStyleTab.getDropAction(aEvent, TST_DRAGSESSION);
+					]]>
+				).replace( // Firefox 3.0.x, 3.5 or later
+					/(if \((accelKeyPressed|isCopy|dropEffect == "copy")\) {)/,
+					<![CDATA[
+						if (TSTTabBrowser.treeStyleTab.performDrop(dropActionInfo, draggedTab))
+							return;
+						$1]]>
+				).replace( // Firefox 3, duplication of tab
+					/(this.selectedTab = newTab;)(\s*\})?/g,
+					<![CDATA[$1;
+						if (dropActionInfo.position == TreeStyleTabService.kDROP_ON)
+							TSTTabBrowser.treeStyleTab.attachTabTo(newTab, dropActionInfo.target);
+					$2]]>
+				).replace( // Firefox 3, dragging tab from another window
+					'else if (draggedTab) {',
+					<![CDATA[$&
+						if (TSTTabBrowser.treeStyleTab.performDrop(dropActionInfo, draggedTab))
+							return;
+					]]>
+				).replace(
+					/(this.loadOneTab\([^;]+\));/,
+					<![CDATA[
+						TSTTabBrowser.treeStyleTab.performDrop(dropActionInfo, $1);
 						return;
-					$1]]>
-			).replace( // Firefox 3, duplication of tab
-				/(this.selectedTab = newTab;)(\s*\})?/g,
-				<![CDATA[$1;
-					if (dropActionInfo.position == TreeStyleTabService.kDROP_ON)
-						TSTTabBrowser.treeStyleTab.attachTabTo(newTab, dropActionInfo.target);
-				$2]]>
-			).replace( // Firefox 3, dragging tab from another window
-				'else if (draggedTab) {',
-				<![CDATA[$&
-					if (TSTTabBrowser.treeStyleTab.performDrop(dropActionInfo, draggedTab))
-						return;
-				]]>
-			).replace(
-				/(this.loadOneTab\([^;]+\));/,
-				<![CDATA[
-					TSTTabBrowser.treeStyleTab.performDrop(dropActionInfo, $1);
-					return;
-				]]>
-			).replace(
-				'document.getBindingParent(aEvent.originalTarget).localName != "tab"',
-				'!TreeStyleTabService.getTabFromEvent(aEvent)'
-			).replace(
-				'var tab = aEvent.target;',
-				<![CDATA[$&
-					var loadDroppedLinkToNewChildTab = (
-							dropActionInfo.position != TreeStyleTabService.kDROP_ON ||
+					]]>
+				).replace(
+					'document.getBindingParent(aEvent.originalTarget).localName != "tab"',
+					'!TreeStyleTabService.getTabFromEvent(aEvent)'
+				).replace(
+					'var tab = aEvent.target;',
+					<![CDATA[$&
+						var loadDroppedLinkToNewChildTab = (
+								dropActionInfo.position != TreeStyleTabService.kDROP_ON ||
+								tab.getAttribute('locked') == 'true' // Tab Mix Plus (or others)
+							);
+						if (!loadDroppedLinkToNewChildTab &&
+							dropActionInfo.position == TreeStyleTabService.kDROP_ON) {
+							loadDroppedLinkToNewChildTab = TreeStyleTabService.dropLinksOnTabBehavior() == TreeStyleTabService.kDROPLINK_NEWTAB;
+						}
+						if (
+							loadDroppedLinkToNewChildTab ||
 							tab.getAttribute('locked') == 'true' // Tab Mix Plus (or others)
-						);
-					if (!loadDroppedLinkToNewChildTab &&
-						dropActionInfo.position == TreeStyleTabService.kDROP_ON) {
-						loadDroppedLinkToNewChildTab = TreeStyleTabService.dropLinksOnTabBehavior() == TreeStyleTabService.kDROPLINK_NEWTAB;
-					}
-					if (
-						loadDroppedLinkToNewChildTab ||
-						tab.getAttribute('locked') == 'true' // Tab Mix Plus (or others)
-						) {
-						TSTTabBrowser.treeStyleTab.performDrop(dropActionInfo, TSTTabBrowser.loadOneTab(getShortcutOrURI(url), null, null, null, bgLoad, false));
-						return;
-					}
-				]]>
-			).replace(
-				/TST_DRAGSESSION/g,
-				(canDropFunctionName == 'canDrop' ?
-					'aDragSession' :
-					'TSTTabBrowser.treeStyleTab.getCurrentDragSession()'
+							) {
+							TSTTabBrowser.treeStyleTab.performDrop(dropActionInfo, TSTTabBrowser.loadOneTab(getShortcutOrURI(url), null, null, null, bgLoad, false));
+							return;
+						}
+					]]>
+				).replace(
+					/TST_DRAGSESSION/g,
+					(canDropFunctionName == 'canDrop' ?
+						'aDragSession' :
+						'TSTTabBrowser.treeStyleTab.getCurrentDragSession()'
+					)
 				)
-			)
-		);
+			);
+		}
 	},
 	onTabbarDragStart : function TSTService_onTabbarDragStart(aEvent, aTabBrowser)
 	{
diff --git a/content/treestyletab/treestyletabbrowser.js b/content/treestyletab/treestyletabbrowser.js
index ed974377..277775c5 100644
--- a/content/treestyletab/treestyletabbrowser.js
+++ b/content/treestyletab/treestyletabbrowser.js
@@ -158,6 +158,7 @@ TreeStyleTabBrowser.prototype = {
 		this.stopRendering();
 
 		var b = this.mTabBrowser;
+		b.tabContainer.treeStyleTab = this;
 
 		this._tabsCache = {};
 
@@ -171,7 +172,7 @@ TreeStyleTabBrowser.prototype = {
 			if (!toggler) {
 				toggler = document.createElement('spacer');
 				toggler.setAttribute('class', this.kTABBAR_TOGGLER);
-				this.tabStrip.parentNode.insertBefore(toggler, this.tabStrip);
+				b.mTabBox.insertBefore(toggler, b.mTabBox.firstChild);
 			}
 		}
 
@@ -350,13 +351,24 @@ TreeStyleTabBrowser.prototype = {
 
 		this.updateTabDNDObserver(b);
 
-		eval('b.getNewIndex = '+
-			b.getNewIndex.toSource().replace(
-				/\.screenX/g, '[this.treeStyleTab.positionProp]'
-			).replace(
-				/\.width/g, '[this.treeStyleTab.sizeProp]'
-			)
-		);
+		if (b.tabContainer && '_getDropIndex' in b.tabContainer) { // Firefox 3.7 or later
+			eval('b.tabContainer._getDropIndex = '+
+				b.tabContainer._getDropIndex.toSource().replace(
+					/\.screenX/g, '[this.treeStyleTab.positionProp]'
+				).replace(
+					/\.width/g, '[this.treeStyleTab.sizeProp]'
+				)
+			);
+		}
+		else if ('getNewIndex' in b) { // Firefox 3.6 or older
+			eval('b.getNewIndex = '+
+				b.getNewIndex.toSource().replace(
+					/\.screenX/g, '[this.treeStyleTab.positionProp]'
+				).replace(
+					/\.width/g, '[this.treeStyleTab.sizeProp]'
+				)
+			);
+		}
 
 		eval('b.moveTabForward = '+
 			b.moveTabForward.toSource().replace(
@@ -416,6 +428,7 @@ TreeStyleTabBrowser.prototype = {
 			)
 		);
 
+/*
 		if ('' in b) { // Firefox 3.7-
 			eval('b._handleKeyEvent = '+
 				b._handleKeyEvent.toSource().replace(
@@ -445,7 +458,7 @@ TreeStyleTabBrowser.prototype = {
 				)
 			);
 		}
-		else if ('_keyEventHandler' in b) { // -Firefox 3.6
+		else */if ('_keyEventHandler' in b) { // Firefox 3.6 or older
 			eval('b._keyEventHandler.handleEvent = '+
 				b._keyEventHandler.handleEvent.toSource().replace(
 					'this.tabbrowser.moveTabOver(aEvent);',
@@ -510,12 +523,14 @@ TreeStyleTabBrowser.prototype = {
 			)
 		);
 
-		eval('b.onTabBarDblClick = '+
-			b.onTabBarDblClick.toSource().replace(
-				'aEvent.originalTarget.localName == "box"',
-				'/^(box|(arrow)?scrollbox|tabs)$/.test(aEvent.originalTarget.localName)'
-			)
-		);
+		if ('onTabBarDblClick' in b) { // Firefox 3.6 or older
+			eval('b.onTabBarDblClick = '+
+				b.onTabBarDblClick.toSource().replace(
+					'aEvent.originalTarget.localName == "box"',
+					'/^(box|(arrow)?scrollbox|tabs)$/.test(aEvent.originalTarget.localName)'
+				)
+			);
+		}
 
 		if ('_onDragEnd' in b) {
 			eval('b._onDragEnd = '+b._onDragEnd.toSource().replace(
@@ -569,7 +584,8 @@ TreeStyleTabBrowser.prototype = {
 		this.onPrefChange('extensions.treestyletab.tabbar.invertTabContents');
 		this.onPrefChange('extensions.treestyletab.tabbar.invertClosebox');
 
-		var tabContextMenu = document.getAnonymousElementByAttribute(b, 'anonid', 'tabContextMenu');
+		var tabContextMenu = document.getAnonymousElementByAttribute(b, 'anonid', 'tabContextMenu') ||
+							document.getAnonymousElementByAttribute(b.tabContainer, 'anonid', 'tabContextMenu');
 		tabContextMenu.addEventListener('popupshowing', this, false);
 		if (!('MultipleTabService' in window)) {
 			window.setTimeout(function(aSelf, aTabBrowser, aPopup) {
@@ -855,6 +871,7 @@ TreeStyleTabBrowser.prototype = {
 		var strip = this.tabStrip;
 		var splitter = this._ensureNewSplitter();
 		var toggler = document.getAnonymousElementByAttribute(b, 'class', this.kTABBAR_TOGGLER);
+		var indicator = b.mTabDropIndicatorBar || b.tabContainer._tabDropIndicator;
 
 		// Tab Mix Plus
 		var scrollFrame, newTabBox, tabBarMode;
@@ -939,7 +956,7 @@ TreeStyleTabBrowser.prototype = {
 					   unexpectedly becomes 0 on the startup. so, we have
 					   to set the width again. */
 					strip.setAttribute('width', aSelf.getTreePref('tabbar.width'));
-					aTabBrowser.mTabDropIndicatorBar.setAttribute('ordinal', 1);
+					indicator.setAttribute('ordinal', 1);
 					strip.setAttribute('ordinal', 30);
 					aSplitter.setAttribute('ordinal', 20);
 					aToggler.setAttribute('ordinal', 40);
@@ -952,7 +969,7 @@ TreeStyleTabBrowser.prototype = {
 				this.setTabbarAttribute(this.kTAB_INVERTED, null, b);
 				this.indentTarget = 'left';
 				delayedPostProcess = function(aSelf, aTabBrowser, aSplitter, aToggler) {
-					aTabBrowser.mTabDropIndicatorBar.setAttribute('ordinal', 1);
+					indicator.setAttribute('ordinal', 1);
 					strip.setAttribute('ordinal', 10);
 					aSplitter.setAttribute('ordinal', 20);
 					aToggler.setAttribute('ordinal', 5);
@@ -998,7 +1015,7 @@ TreeStyleTabBrowser.prototype = {
 				this.setTabbarAttribute(this.kTABBAR_POSITION, 'bottom', b);
 				this.indentTarget = 'bottom';
 				delayedPostProcess = function(aSelf, aTabBrowser, aSplitter, aToggler) {
-					aTabBrowser.mTabDropIndicatorBar.setAttribute('ordinal', 1);
+					indicator.setAttribute('ordinal', 1);
 					strip.setAttribute('ordinal', 30);
 					aSplitter.setAttribute('ordinal', 20);
 					aToggler.setAttribute('ordinal', 40);
@@ -1009,7 +1026,7 @@ TreeStyleTabBrowser.prototype = {
 				this.setTabbarAttribute(this.kTABBAR_POSITION, 'top', b);
 				this.indentTarget = 'top';
 				delayedPostProcess = function(aSelf, aTabBrowser, aSplitter, aToggler) {
-					aTabBrowser.mTabDropIndicatorBar.setAttribute('ordinal', 1);
+					indicator.setAttribute('ordinal', 1);
 					strip.setAttribute('ordinal', 10);
 					aSplitter.setAttribute('ordinal', 20);
 					aToggler.setAttribute('ordinal', 5);
@@ -1158,6 +1175,7 @@ TreeStyleTabBrowser.prototype = {
 		delete this._autoHide;
 
 		var b = this.mTabBrowser;
+		delete b.tabContainer.treeStyleTab;
 
 		this.getTabsArray(b).forEach(function(aTab) {
 			this.destroyTab(aTab);
diff --git a/modules/utils.js b/modules/utils.js
index e8327ac6..2baac84b 100644
--- a/modules/utils.js
+++ b/modules/utils.js
@@ -789,14 +789,18 @@ var TreeStyleTabUtils = {
 	
 	getTabBrowserFromChild : function TSTUtils_getTabBrowserFromChild(aTabBrowserChild) 
 	{
-		if (!aTabBrowserChild) return null;
+		if (!aTabBrowserChild)
+			return null;
 
-		if (aTabBrowserChild.__treestyletab__linkedTabBrowser)
+		if (aTabBrowserChild.__treestyletab__linkedTabBrowser) // tab
 			return aTabBrowserChild.__treestyletab__linkedTabBrowser;
 
-		if (aTabBrowserChild.localName == 'tabbrowser')
+		if (aTabBrowserChild.localName == 'tabbrowser') // itself
 			return aTabBrowserChild;
 
+		if (aTabBrowserChild.tabbrowser) // tabs, Firefox 3.7 or later
+			return aTabBrowserChild.tabbrowser;
+
 		var b = this.evaluateXPath(
 				'ancestor::xul:tabbrowser | '+
 				'ancestor::xul:tabs[@tabbrowser]',