Odd ghosting in Excel when alternating between worksheets

Greetings.

I'm on a Intel DH61BE board, have updated the graphics driver to 9.17.10.3517, run two drives in Raid 1, and use the VGA output to an HP 23" monitor.  Ever since I've had this board I get a very odd ghosting effect when I use Excel and switch (Alt-Tab) between open worksheets.  Here is an example:

Also if I switch too often too quickly between worksheets then Excel will hang and force me to close all open worksheets.  Needless to say this is a very frustrating experience.  I have searched high and low for any other users experiencing the same problem but so far I am the only one.

I would be very appreciative for suggestions.

Thanks.

Bruce