OpenGL: Black screen flash on mouse click

Problem Description: In OpenGL games (Tribes 2, Quake Wars) I started getting a black screen flash when pressing any mouse button. The problem is only in fullscreen mode, not windowed. Tribes 2 in DirectX mode doesn't have the problem and all DirectX games are fine. The problem is only OpenGL, fullscreen. Any of the 5 main mouse buttons will initiate the problem. It's very distracting. It happens in menus and ingame. I click to fire, press mouse4 to reload, whatever, screen flashes black. If I hold it down, it only flashes once, on the initial click. Registering the mouse button press causes it, not the hardware input: If I bind the mouse buttons to something else in my Logitech drivers, they won't trigger it. It only does it on official Mouse 1, Mouse2, etc presses.

Attempted Fixes: New Video card drivers, turning off UAC, **** with nvidia driver, game settings, different mice.

Recent changes: Could be anything. I stopped playing Quake Wars a few months ago and was only playing DX games. I started playing Tribes 2 recently, assumed it was a Tribes problem. Started playing Quake Wars again today and it has the same problem.

Operating System: Vista Business 32-bit

System Specs: Core2Duo e6600, nvidia 8800GTS, 4GB Corsair 800mhz DDR2. Western Digital Black hard drive. Gigabyte motherboard. Logitech G9 and MX Revolution.

It's bizarre I can't find anything on this issue anywhere. I'm running a common hardware and software setup. It started out of nowhere. This should not be happening. Any ideas?