All I can think of is you might need to try "rebooting". There is a tiny hole in the bottom of the camera (inside the place where you would screw in a tripod). Try sticking a paper clip in the tiny hole a push for about 5-10 seconds. Mine has frozen before and that resets it. Do that, then try hooking it back up to your computer.
Generally yes. The picture quality is excellent. equivant to a good DVD. Sound quality is also excellent without any humming or self generated background noise.
However, I noticed that if I place the camera on a table for example and there is something off to the side but in the view of the camera, the auto focus will become confused and the person being filmed is then out of focus. Also, while they tout 120 minutes of recording, the best I've gotten without a re-start is about 70-minutes.