Also, if the video plays in the camera, but not on the computer, try ripping the video another way. Something like this:
https://www.youtube.com/watch?v=dG8baVEmlz4
or
http://windows.microsoft.com/en-us/windows-vista/import-video-from-a-videotape
Sounds like a bad tape...
I don't know much about this, however I've shot digital tape and was able to pull from the tape to my PC.
Do the other 2 tapes work okay?