As I see, many visitors from Google come to my blog after running query like “ReSharper 3 menus disabled”, “ReSharper 3 not working” and similar. Well, I have good news and bad news for you. Good news is, I installed ReSharper once again and it works now. The bad news however is, that I reinstalled Visual Studio first, so I’m aware that it may not be acceptable solution for some people. I needed to install VSIP Factory and my GAX kept throwing errors, so I got mad, uninstalled the whole thing (meaning Visual Studio and all things on top of it), and Installed Visual Studio Pro (Instead of Team System I had earlier), and now it works. So if you need ReSharper, and reinstalling Visual Studio is not an issue – it could help.
On the bright side for all other – JetBrains heard that it’s a serious problem, they reopened the issue with high priority, and have update scheduled for 3.0.2 release. If you can – help them by providing listing of your ‘ReSharper\v3.0\vs8.0\bin’ folder because mine for obvious reasons would not be very useful.
Hope this helps.