OK, I never had that one before, but it basically is the same (although one might hope Windows would include a safeguard against that). The difference amongst systems might be due to timing differences (they don't play by the book exactly when the process is exiting anyway); or just perhaps some Service Pack just added a safeguard! If you ever find out, please let us know. :) Luc Pattyn [My Articles] Nil Volentibus Arduum

Movies get played at 24 or 25 frames per second, which is faster than the human eye can discern, resulting in smooth films. So there is no point in having a timer period which is less than say 30 milliseconds. What you should do however, is in each repaint use the actual time, not the predicted or expected one, to calculate how the new frame should look; doing it that way you'd compensate for most of the timing jitter a Windows PC may experience. :) Luc Pattyn [My Articles] Nil Volentibus Arduum

Nah, WCF sucks. I will never use it again. It is easy to implement though. We have a couple of WCF components in my current project (not my idea!). WCF is slow (too much XML traffic) and has no push mechanism. I don't think WCF would scale too well either. The only thing that scales into 10's of thousands of connections per server is going to be TCP/IP (or UDP) using IOCPs. Not sure if the OP has to go that far though :).