I setup a new laptop on the weekend and this morning found a crazy bug – my SharePoint 2010 and Project Server 2010 menus and ribbon would not work at all, basically rendering my laptop useless unless I could figure this out.
After much poking around in F12 Developer Tools and searching around the web, I finally figured out the solution myself.
I had dragged the IE icon to my taskbar and for some reason it was loading the 32 bit version of IE instead of 64 bit. After starting IE using the 64 bit version all was well.
I’m not sure what the exact issue was – I have used both 32bit and 64 bit IE 8 and 9 browsers on other computers and never had any issues loading SharePoint 2010 menu items.
Anyway hope that helps someone else.