Added a check to make sure the plugin isn't loaded more than once

plugin/indent_guides.vim

@@ -1,6 +1,11 @@
 " Author:   Nate Kane <nathanaelkane AT gmail DOT com>
 " Homepage: http://github.com/nathanaelkane/vim-indent-guides
 
+if exists('g:loaded_indent_guides') || &cp
+  finish
+endif
+let g:loaded_indent_guides = 1
+
 function! s:IndentGuidesToggle()
   call indent_guides#toggle()
 endfunction