Haven't had these since I softmodded my GeForce to a Quadro and reformatted my harddrive... though just for reference's sake I'll post them up here.

1) While texturing a model Maya after about an hour of working randomly decides to replace ALL my viewport commands (orbit, zoom, pan, etc.) with ZoomWindow.

2) Sometimes shading of objects goes crazy... as exampled here:

And the normals were all facing the correct way.

3) Even though all the normals were facing the correct way to begin with, upon exporting to WRL or OBJ all the smoothing groups disappear, and the normals randomly pick a direction.

4) (recent) Maya randomly decides to not include all the polygons in a properly UV snapshot (though when tried again without modifying the UVs it did -- though with the UVs offset a few pixels from where they should be.)