When i am editing a drawing by exploding grouped objects. attempting to move objects, copying objects. stretching objects and numerous other commands the pc often crashes. Most times I can retrieve a a recovered file and some times nothing is saved. I recently upgraded my pc with the Quad pro 2000 video card for Sketchup. that might have helped some. I have also attempted to use the 3dmousse to rotate views but it does not work. It seems that the 3d mouse only works on small files with little memory.
How big is the file you’re working on? Open Model Info>Statistics and screen shot that information.