Rotate problem with sw2010

I run SW 2010 on win7 64. The system, Dell 3400,  is about 2 yrs old with FX570  video card

The rotate command is not working properly.  it stops working many times a day. All I see is a small window on the screen with part of the model rotated in it

Anyone here has experienced this weird behavior? Is there a way to fix this

Thanks

SolidworksGeneral