The other day I had an annoying problem accessing SharePoint sites. I am running Windows 7, IE8 and Office 2007 and Office 2010 Beta.
Any internal SharePoint site continued to throw the error of element not found for init.js
It only happened on my desktop (my laptop worked just fine). I tried clearing the temporary internet files, browser cache, even uninstalling and reinstalling IE8.
Nothing worked, I finally found the solution here – http://social.technet.microsoft.com/Forums/en-US/sharepointgeneral/thread/41e1874f-7825-4bfe-ba4c-37255d198df2
So, I opened up SharePoint Designer 2007, ran the diagnostic tool in the Help menu, restarted IE and everything was back to working as normal.