I'm using Vista x64, but it should be the same on 7. I did do a complete reinstall when beta 4 showed up. I even deleted all the elemental files I could find before installing.
Explorer pic
I think that did it. I upgraded from beta 3 (which didn't have the Games Explorer stuff in yet). So to test it I uninstalled and then reinstalled, and now I have the Games Explorer entry.
Mystery solved, thanks for the help!