If your cable problem is a physical Firewire issue with either the camcorder or the computer port, a repair could cost serious money (up to half of the new cost of your camcorder.) Â So if you have a friend with a camcorder using Firewire and a computer that captures the video, try swapping the camcorders with each other to see if the problem occurs with only one of your Firewire ports.
Otherwise your next option would be to get another miniDV camcorder to act as an edit deck. I've gotten some good deals from eBay (and really screwed a couple of times.) So I still watch for deals & recommended sellers. Hopefully it will turn out to be a desktop Firewire problem and can be fixed with a new card.
Good luck tracking it down and solving the dilemma.