Steam: Lockup, forced to restart computer

[kelderos]

Every now and then Kings Bounty locks up to the point where I can't ctrl +alt +delete to get out of the game and back to my desktop, I am forced to restart. Usually before this happens the game graphics seem to glitch out. I see shadows of light (in the second starting trial, the circle of candles for instance. when I moved my camera around the light from the circle of candles stayed in place)

Recently, it's taken to just locking up for no reason. Usually after I click to move around or pick something up. Anyone know what's up?