Hi aareminer, if your screen is flickering strangely that's a very unusual problem and the only thing I can really think of is maybe you have a buggy video driver. It's possible that Mastercam and Spaceclaim just by chance do not happen to trigger the problem, video driver bugs can be like that.

So my main recommendation is to update your video driver and see if that improves things.

Also if you are running a virus checking system may be that's interfering with MoI in some way so try temporarily disabling that and see if that makes any difference.

But a flickering screen that does not go away until you do Ctrl+Alt+Delete sounds very much like a video driver problem to me.

- Michael