diff --git a/content/treestyletab/treestyletab.js b/content/treestyletab/treestyletab.js
index fcf3ecf7..ccae66af 100644
--- a/content/treestyletab/treestyletab.js
+++ b/content/treestyletab/treestyletab.js
@@ -12,21 +12,21 @@ var TreeStyleTabService = {
 		return this.utils.currentTabbarPosition;
 	},
 	set currentTabbarPosition(aValue)
-	{
-		if ('UndoTabService' in window && UndoTabService.isUndoable()) {
-			var current = this.utils.currentTabbarPosition;
+	{
+		if ('UndoTabService' in window && UndoTabService.isUndoable()) {
+			var current = this.utils.currentTabbarPosition;
 			var self = this;
 			UndoTabService.doOperation(
 				function() {
 					self.utils.currentTabbarPosition = aValue;
-				},
-				{
-					label  : self.treeBundle.getString('undo_changeTabbarPosition_label'),
-					name   : 'treestyletab-changeTabbarPosition',
-					data   : {
-						oldPosition : current,
-						newPosition : aValue
-					}
+				},
+				{
+					label  : self.treeBundle.getString('undo_changeTabbarPosition_label'),
+					name   : 'treestyletab-changeTabbarPosition',
+					data   : {
+						oldPosition : current,
+						newPosition : aValue
+					}
 				}
 			);
 		}
@@ -288,7 +288,7 @@ var TreeStyleTabService = {
 		var appcontent = document.getElementById('appcontent');
 		appcontent.addEventListener('SubBrowserAdded', this, false);
 		appcontent.addEventListener('SubBrowserRemoveRequest', this, false);
-
+
 		window.addEventListener('UIOperationHistoryUndo:TabbarOperations', this, false);
 		window.addEventListener('UIOperationHistoryRedo:TabbarOperations', this, false);
 
@@ -344,10 +344,44 @@ var TreeStyleTabService = {
 	updateTabDNDObserver : function TSTService_updateTabDNDObserver(aObserver) 
 	{
 		if (aObserver.tabContainer &&
-			aObserver.tabContainer.tabbrowser == aObserver)
+			aObserver.tabContainer.tabbrowser == aObserver) { // Firefox 3.7 or later
 			aObserver = aObserver.tabContainer;
+			aObserver.addEventListener('dragstart', this, true);
+			aObserver.addEventListener('dragover', this, true);
+			aObserver.addEventListener('dragleave', this, true);
+		}
 
-		if ('_onDragStart' in aObserver) { // Firefox 3.5 or later
+		var canDropFunctionName = '_setEffectAllowedForDataTransfer' in aObserver ?
+				'_setEffectAllowedForDataTransfer' : // Firefox 3.5 or later
+				'canDrop' ; // Firefox 3.0.x
+		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(arguments[0], this)) {
+							return TST_DRAGDROP_DISALLOW_RETRUN_VALUE;
+						}
+						$1
+					]]>
+				).replace(
+					/TST_DRAGDROP_DISALLOW_RETRUN_VALUE/g,
+					(canDropFunctionName == 'canDrop' ?
+						'false' :
+						'dt.effectAllowed = "none"'
+					)
+				)
+			);
+		}
+
+		if ('_onDragStart' in aObserver) { // Firefox 3.5 - 3.6
 			eval('aObserver._onDragStart = '+
 				aObserver._onDragStart.toSource().replace(
 					'if (target.localName == "tab"',
@@ -373,38 +407,8 @@ var TreeStyleTabService = {
 			);
 		}
 
-		var canDropFunctionName = '_setEffectAllowedForDataTransfer' in aObserver ?
-				'_setEffectAllowedForDataTransfer' : // Firefox 3.5 or later
-				'canDrop' ; // Firefox 3.0.x
-		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 3.5 - 3.6
 				'onDragOver' ; // Firefox 3.0.x
 		if (dragOverFunctionName in aObserver) {
 			eval('aObserver.'+dragOverFunctionName+' = '+
@@ -421,7 +425,7 @@ var TreeStyleTabService = {
 		}
 
 		var dragExitFunctionName = '_onDragLeave' in aObserver ?
-				'_onDragLeave' : // Firefox 3.5 or later
+				'_onDragLeave' : // Firefox 3.5 - 3.6
 				'onDragExit' ; // Firefox 3.0.x
 		if (dragExitFunctionName in aObserver) {
 			eval('aObserver.'+dragExitFunctionName+' = '+
@@ -501,7 +505,18 @@ var TreeStyleTabService = {
 			);
 		}
 	},
-	onTabbarDragStart : function TSTService_onTabbarDragStart(aEvent, aTabBrowser)
+	destroyTabDNDObserver : function TSTService_destroyTabDNDObserver(aObserver)
+	{
+		if (aObserver.tabContainer &&
+			aObserver.tabContainer.tabbrowser == aObserver) { // Firefox 3.7 or later
+			aObserver = aObserver.tabContainer;
+			aObserver.removeEventListener('dragstart', this, true);
+			aObserver.removeEventListener('dragover', this, true);
+			aObserver.removeEventListener('dragleave', this, true);
+		}
+	},
+	
+	onTabbarDragStart : function TSTService_onTabbarDragStart(aEvent, aTabBrowser) 
 	{
 		var dt = aEvent.dataTransfer;
 		dt.mozSetDataAt(
@@ -524,7 +539,8 @@ var TreeStyleTabService = {
 		aEvent.stopPropagation();
 		aTabBrowser.treeStyleTab.tabbarDNDObserver.readyToStartDrag();
 	},
-	checkCanTabDrop : function TSTService_checkCanTabDrop(aEvent, aTabBrowser)
+ 
+	checkCanTabDrop : function TSTService_checkCanTabDrop(aEvent, aTabBrowser) 
 	{
 try{
 		var session = this.getCurrentDragSession();
@@ -547,7 +563,8 @@ catch(e) {
 		return false;
 }
 	},
-	processTabDragOverEvent : function TSTService_processTabDragOverEvent(aEvent, aTabBrowser)
+ 
+	processTabDragOverEvent : function TSTService_processTabDragOverEvent(aEvent, aTabBrowser) 
 	{
 try{
 		var session = this.getCurrentDragSession();
@@ -556,13 +573,25 @@ try{
 		var info = this.getDropAction(aEvent, session);
 
 		// auto-switch for staying on tabs (Firefox 3.0 or later)
-		var isHTML5Event = '_setEffectAllowedForDataTransfer' in aTabBrowser;
-		if (isHTML5Event &&
+		var setEffectAllowedFunc;
+		if (aTabBrowser._setEffectAllowedForDataTransfer) {
+			setEffectAllowedFunc = function(aEvent) {
+				return aTabBrowser._setEffectAllowedForDataTransfer(aEvent);
+			};
+		}
+		else if (aTabBrowser.tabContainer &&
+			aTabBrowser.tabContainer._setEffectAllowedForDataTransfer) {
+			setEffectAllowedFunc = function(aEvent) {
+				return aTabBrowser.tabContainer._setEffectAllowedForDataTransfer(aEvent);
+			};
+		}
+
+		if (setEffectAllowedFunc &&
 			info.target &&
 			!info.target.selected &&
 			'mDragTime' in aTabBrowser &&
 			'mDragOverDelay' in aTabBrowser) {
-			let effects = aTabBrowser._setEffectAllowedForDataTransfer(aEvent);
+			let effects = setEffectAllowedFunc(aEvent);
 			if (effects == 'link') {
 				let now = Date.now();
 				if (!aTabBrowser.mDragTime)
@@ -579,8 +608,8 @@ try{
 			).singleNodeValue)
 			this.clearDropPosition();
 
-		if (isHTML5Event ?
-				(aTabBrowser._setEffectAllowedForDataTransfer(aEvent) == 'none') :
+		if (setEffectAllowedFunc ?
+				(setEffectAllowedFunc(aEvent) == 'none') :
 				!aTabBrowser.canDrop(aEvent, session)
 			)
 			return true;
@@ -591,7 +620,8 @@ try{
 			info.position == this.kDROP_AFTER ? 'after' :
 			'self'
 		);
-		aTabBrowser.mTabDropIndicatorBar.setAttribute('dragging', (info.position == this.kDROP_ON) ? 'false' : 'true' );
+		var indicator = aTabBrowser.mTabDropIndicatorBar || aTabBrowser.tabContainer._tabDropIndicator;
+		indicator.setAttribute('dragging', (info.position == this.kDROP_ON) ? 'false' : 'true' );
 		return (info.position == this.kDROP_ON || aTabBrowser.getAttribute(this.kTABBAR_POSITION) != 'top')
 }
 catch(e) {
@@ -599,6 +629,30 @@ catch(e) {
 }
 	},
  
+/* tab DND listening for Firefox 3.7 or later */ 
+	
+	onTabDNDObserverDragStart : function TSTService_onTabDNDObserverDragStart(aEvent) 
+	{
+		var tabbar = aEvent.currentTarget;
+		if (tabbar.treeStyleTab.tabbarDNDObserver.canDragTabbar(aEvent))
+			tabbar.treeStyleTab.onTabbarDragStart(aEvent, tabbar.tabbrowser);
+	},
+ 
+	onTabDNDObserverDragOver : function TSTService_onTabDNDObserverDragOver(aEvent) 
+	{
+		var tabbar = aEvent.currentTarget;
+		if (tabbar.treeStyleTab.processTabDragOverEvent(aEvent, tabbar.tabbrowser))
+			aEvent.stopPropagation();
+	},
+ 
+	onTabDNDObserverDragLeave : function TSTService_onTabDNDObserverDragLeave(aEvent) 
+	{
+		var tabbar = aEvent.currentTarget;
+		var tabbarFromEvent = this.getTabbarFromChild(aEvent.relatedTarget);
+		if (!tabbarFromEvent)
+			tabbar.treeStyleTab.clearDropPosition();
+	},
+   
 	overrideGlobalFunctions : function TSTService_overrideGlobalFunctions() 
 	{
 //		window.__treestyletab__BrowserCustomizeToolbar = window.BrowserCustomizeToolbar;
@@ -945,7 +999,7 @@ catch(e) {
 		var appcontent = document.getElementById('appcontent');
 		appcontent.removeEventListener('SubBrowserAdded', this, false);
 		appcontent.removeEventListener('SubBrowserRemoveRequest', this, false);
-
+
 		window.removeEventListener('UIOperationHistoryUndo:TabbarOperations', this, false);
 		window.removeEventListener('UIOperationHistoryRedo:TabbarOperations', this, false);
 
@@ -1043,6 +1097,11 @@ catch(e) {
 						this.currentTabbarPosition = aEvent.entry.data.newPosition;
 						return;
 				}
+
+			// tab drag drop listeners for Firefox 3.7 or later
+			case 'dragstart': return this.onTabDNDObserverDragStart(aEvent);
+			case 'dragover': return this.onTabDNDObserverDragOver(aEvent);
+			case 'dragleave': return this.onTabDNDObserverDragLeave(aEvent);
 		}
 	},
 	
diff --git a/content/treestyletab/treestyletabbrowser.js b/content/treestyletab/treestyletabbrowser.js
index d4241a23..d3bf9a14 100644
--- a/content/treestyletab/treestyletabbrowser.js
+++ b/content/treestyletab/treestyletabbrowser.js
@@ -342,7 +342,7 @@ TreeStyleTabBrowser.prototype = {
 			)
 		);
 
-		this.updateTabDNDObserver(b);
+		TreeStyleTabService.updateTabDNDObserver(b);
 
 		if (b.tabContainer && '_getDropIndex' in b.tabContainer) { // Firefox 3.7 or later
 			eval('b.tabContainer._getDropIndex = '+
@@ -1266,6 +1266,8 @@ TreeStyleTabBrowser.prototype = {
 
 		b.removeEventListener('MultipleTabHandlerTabsClosing', this, false);
 
+		TreeStyleTabService.destroyTabDNDObserver(b);
+
 		this.tabbarDNDObserver.destroy();
 		delete this._tabbarDNDObserver;
 		this.panelDNDObserver.destroy();
@@ -1274,7 +1276,8 @@ TreeStyleTabBrowser.prototype = {
 		this.scrollBox.removeEventListener('overflow', this, true);
 		this.scrollBox.removeEventListener('underflow', this, true);
 
-		var tabContextMenu = document.getAnonymousElementByAttribute(b, 'anonid', 'tabContextMenu');
+		var tabContextMenu = document.getAnonymousElementByAttribute(b, 'anonid', 'tabContextMenu') ||
+							document.getAnonymousElementByAttribute(b.tabContainer, 'anonid', 'tabContextMenu');
 		tabContextMenu.removeEventListener('popupshowing', this, false);
 
 		var allTabPopup = document.getAnonymousElementByAttribute(b.mTabContainer, 'anonid', 'alltabs-popup');
@@ -2839,7 +2842,10 @@ TreeStyleTabBrowser.prototype = {
 				return info;
 			}
 			else {
-				info.target = tabs[Math.min(b.getNewIndex(aEvent), lastTabIndex)];
+				let index = b.getNewIndex ?
+								b.getNewIndex(aEvent) :
+								b.tabContainer._getDropIndex(aEvent) ;
+				info.target = tabs[Math.min(index, lastTabIndex)];
 			}
 		}
 		else {
diff --git a/modules/utils.js b/modules/utils.js
index 8e320a37..b3e91cb3 100644
--- a/modules/utils.js
+++ b/modules/utils.js
@@ -723,15 +723,20 @@ var TreeStyleTabUtils = {
 		return null;
 	},
  
-	getTabbarFromEvent : function TSTUtils_getTabbarFromEvent(aEvent) 
+	getTabbarFromChild : function TSTUtils_getTabbarFromChild(aNode) 
 	{
 		return this.evaluateXPath(
 				'ancestor-or-self::*[contains(concat(" ", normalize-space(@class), " "), " tabbrowser-strip ") or (local-name()="tabs" and @tabbrowser)]',
-				aEvent.originalTarget || aEvent.target,
+				aNode,
 				Ci.nsIDOMXPathResult.FIRST_ORDERED_NODE_TYPE
 			).singleNodeValue;
 	},
  
+	getTabbarFromEvent : function TSTUtils_getTabbarFromEvent(aEvent) 
+	{
+		return this.getTabbarFromChild(aEvent.originalTarget || aEvent.target);
+	},
+ 
 	cleanUpTabsArray : function TSTUtils_cleanUpTabsArray(aTabs) 
 	{
 		var newTabs = [];