Well at first I had the similar problem like yours which was due to that the webcam was UVC. In the one of the menus in stream, only Yuv2 would work which you can therefore figure that Yuv2 support is the issue.
Solution: Sadly your webcam is the problem. If your cam does not use Yuv2 then you might as well forget this solution. If it does then go buy one of these 3 things: Wii remote ($18-$39.99) or a logitech $20 cam, or a Ps2/Ps3 eye.
Wii: very high fps up to 120, jitter 20-30 (quite good for a high fps)
Logitech cam: average 30fps, 1-10 jitter (depends on type of cam)
PlayStation 2/3 eye: Very good about 80-100 fps (not sure) and average jitter (not sure either)
2nd Solution: Get a better driver, can't give you anything simpler than that.
If possible give your pc specs and your webcams specs, include your video card.
EDit: Get a Microsoft Lifecam Vx1000, I plan on getting one soon as for now, I'm messing with a gigaware pc camera which works but recently gave a bsod.