Not gonna lie. Somehow I never noticed this post.
I've had 2 webcams, both of which work fine for me. One is a logitech and I think the other was a creative.
I've had 2 tablets, each with 2 cameras. On my first tablet, I could view one camera but not the other, and I could not do image-capture. On my new tablet, I can't get either camera to work. So I can definitely reproduce camera problems.
I think the reason I can't do image capture on some cameras is because they are sending a compressed stream instead of an RGB24 stream. I'm not sure. I've never had corrupted video though. But what you say about multiple columns gets me thinking.
Now that I'm running my tablet in my car, and I see that stupid camera icon grayed out, I'll get to the bottom of it one way or another.