Well if the file is 30 MB then it's not going to be a very long movie is it. Yep over 600 MB is what you should be aiming for. You can try Bitzi lookup to see if it's listed on their database before or during downld. If not then report your findings of the bad ones you got. I'm not a Bearshare user so I can't explain how to do Bitzi lookup with BS. Another BS user will need to clue you how to do that.
So who one the cycling?