This is driving me crazy. Ever since I installed ReSharper 4, F12 no longer seems to work. If you look at the all the ReSharper short cuts in the Goto sub menu Declar
I had just installed Pulover’s Macro Creator and F12 was set as the global hotkey to pause a macro. It was intercepting the keypress before it had a chance to get to VS.
Solution is to change that hotkey to something else. I chose Ctrl-F12. The input box is on the top right of the Pulover window.