The 602 is a still cam first, so sensitivity is what you get in stills, movie mode only strings the stills together at 640X480 @30fps, and I believe higher compression.
Despite my previous comment, I'm now wondering whether the sensitivity options like 1600 ASA at 1Mpix could be used. I don't think the cam processor could acquire 3Mpix and pixel share to give enhanced sensitivity, for movies. Sensitivity might be fixed in movie mode. You've only got an f2.8 lens going for you.
So I suspect its movie sensitivity is default 200ASA. Not much good for movies indoors by low light. It wouldn't be easy to get a high res, high fps and use MJPEG with these constraints. That's why dv movie cams are the better cams for this work.
Try shooting stills of the same indoor scene in 'P' mode at all the ASA options, compare with some movie pause frames to work out which one the cam is using. I doubt if it's that clever to be adjusting it in movie - but you never know!