I am having all kinds of problems.
Originally I was running Win 7 with no problems at all.
6 weeks ago, I start getting problems, units not downloading, units not running.
I update to cat 9.6 and all hell breaks loose. Drivers crashing every 30 sec to a minute just horrible.
Yesterday, I get off 7 and go to Vista, cat 9.6 and exact same problems.

Today I go back to 7 with cat 9.4, and get it breathing, but it is still not running right.
Not getting new work, not running. I have to suspend the CPU work to get the GPU work going, even though I have it set 90/10 biased to the GPU project. and I am getting constant screen freezes when I never got any before originally.

have a look here:

http://milkyway.cs.rpi.edu/milkyway/forum_thread.php?id=941