Active Desktop Recovery

Is there a list of possible causes for the Active Desktop Recovery? We are

getting this on a number of our domain pc's. We use active desktop via group

policy to deploy our standard desktop backgrounds so i can't turn it off but

i was wondering what causes the problem. I have searched some forums and

there are some laughable comments and solutions on there. Is this caused by a

file corruption? We have a reg fix that fixes the problem by resetting the

DeskHtmlVersion key to 0 but i'm not sure what that does exactly.

Anyone any idea what the true cause of the problem is?

cheers

Craig