A MacFixIt reader who has been having significant problems with data corruption on a FireWire 800 drive connected to a PowerMac G5 reports that the problem has been narrowed down to a conflict with the MOTU 828mkII digital audio interface connected to a different (FireWire 400) port:
"[Long, detailed description of problem and troubleshooting steps.] There were no other FW800 devices, and no other external devices but the MOTU 828mkII. I used the 828 for Midi input and audio I/O. The 828 was on the FW400 ports, so it didn?t seem to make sense to me that it could be conflicting. I tried different sample rates selected while transferring files and noticed changes in the glitches again. After disconnecting the MOTU and using the internal audio for playback, all problems ceased. One drive, two drives, mounted during startup and shut down, no matter what I tried I could not get a glitch. Power the MOTU back up, and the corruption is back, finder swaps the drives? etc."