I had the same suspicion, so I tried my firewire interface through a PCMCIA firewire controller to test it and it didnt change. I also got out the MBOX just to be sure and it did the same thing.
After things started going wrong I used disk utility to verify the disk and it failed. I tried the repair in disk utility and it failed as well. Afterwards I tried to just back it all up and format just to find that most of the data corrupted. I dont know if it was messed up to begin with or I messed it up by trying to repair it but I'd really like to know if its my fault or just another hard drive accident.
Mark