What went wrong? IAF or OIS issue?
 

Last week, I was recording an event with the HV20, and I was moving it around on a dolly. I was using IAF, and the picture would go focus hunting way too often. I suppose it's a problem with all autofocus systems, but I've used the HC-1 in the same situation with it's autofocus, and there wasn't too many problems with focus. But also, I'm wondering if the OIS has anything to do with it. I suspect it may be a problem with the vibrations caused by the dolly. I know that some of the people who have tested the HV20 mounted on cars and motorcycles have said that the results are less than optimal, so I'm wondering if that's what I'm seeing here. Maybe I'm confusing vibration with focus, and it has nothing to do with it. Anyway, just thought I'd ask.

edit: Now that I think about it... shouldn't I turn stabilization off when I'm on a dolly/tripod? I think that was my problem... but I'm not sure that it explains the excessive focus hunting.

Absolutely.

I have found that 'Instant' Auto Focus hunts more than standard auto-focus when it gets confused. If the camera is doing this simply switch to 'Normal' Auto Focus and I bet your hunting would go away.

At a big store a rep from Canon was showing me the HV20. One selling point was the Instant Autofocus. The rep said that if you're doing a documentary the IAF is a great feature, but you may not want to use it too much because after a while it can make you a little seasick.

I think it's made to point the camera at something, get quick focus, and stay on that something. Great for Papparazzzi home videos on Sunset Blvd. when you just get quick glimpses of your subject.