(I found the original post a little confusing. Even now.)

There is a chance the file is corrupt.

If it happens on a frequent basis, have you repaired your comp using disk utility from the startup disk. Also doing a safe boot & repairing permissions: http://www.gnutellaforums.com/showth...6094#post96094

For apps to misbehave like that sounds like either/both a repair & permissions issue.

I suppose you could also try alternative players. MPlayer is the equivalent of VLC. You could also try DivX Player. Also, enable all or most of your QuickTime MIME plug-ins; see: http://www.gnutellaforums.com/showth...threadid=26816

I have also found some videos don't reliably play all the way thru. Using VLC I need to let it play & not attempt to fast forward so to speak. I suspect it has something to do with the way it was encoded.

I hope this is of some help to you.