[Spinning and Staring at Ceiling]

That actually seems to have solved it. I had an N64 adapter plugged in. After unplugging it, it runs just fine. Wouldn't have thought of that. Thanks!!!

[Spinning and Staring at Ceiling]

After installing the newest update (4.02), whenever I start a game, my character spins in place and stares at the ceiling. I can counter the movement by moving my mouse in the opposite, direction, but it continues right after I stop. It happens in both multiplayer (tested multiple servers) and single-player skirmish mode. I messed the settings, nothing seemed to change it. It used to work fine before the latest update. No one who was playing seemed to know how to fix it (at the time).

I have also tried uninstalling and reinstalling, to no effect.