I had this problem, found a work around and have had no problem with it for weeks. The first thing I did was get the latest update of Final Cut 7. It worked okay for a bit, but the problem came back.
Someone on the forum mentioned that freeze frames could be a problem. I noticed that the first shot on my sequence was a freeze frame. Once I removed it, I no longer had the problem. I think it’s a bug with version 7.
Unfortunately you have to get to the problem before the name changes. I would go into your back up and find the latest version before the names have changed. Then I’d remove your freeze frames.