Window Randomly Minimizes?

[Chanus]

Apologies if this is posted elsewhere, nothing came up on a search.

Is there a known issue with the game window randomly minimizing? In fullscreen, it collapses and switches to Windowed. The game doesn't crash, it keeps running normally. The only thing I've noticed is it seems to happen when I click either mouse button, but not every time, so I don't know if that's a coincidence or not.

Windows 7
Wireless Microsoft laptop mouse
Acer Aspire 5532
AMD Athlon 64 1.6 GHz
ATI Radeon HD3200 graphics (on-board)
3GB RAM

Dunno what else would be pertinent, if anything.