I thought I was the only one having this problem. I'm running windows 7 Professional SP1, and Yawcan seems to run great for a few hours or so, then it freezes my computer. The only thing I have noticed is that when Yawcam runs, I can see javaw.exe run in the task manager, and it usually takes up 4-7 percent of the CPU time. But then after a few hours, the system freezes (actually it slows down to a crawl where it take several minutes to open and close applications), the javaw.exe is now running at 15-20% sometimes higher of the CPU time. the other CAM software I have tried do no have this problem but they don't use javaw.exe either. I really like to use Yawcam because it's the simplest of all the webcam software out there (and it's free). I think it's the javaw.exe that is causing the problem and I would like to see if Yawcam can run without it.
Well, It turns out that another application running on the system was causing Yawcam to freeze and freezing my whole system in fact. Once I'd removed the offending software, Yawcam has been running like a charm. With that being said, I retract my earlier comment above.