External Drive & FW Issues - Daisy Chaining

Hi there,

I really hope somebody can help, I am at a loss here.

For some reason, my Mac decided that it wasn't going to like daisy chaining drives on the FW800 port.

I used to have a series of drives all connected to the FW800 port on the back of the mac. A FW800 600mb RAID, a FW800 1tb RAID Drive and a FW400 750GB External. They all worked great with no problems.

Two days ago, they started randomly dropping out. They would just disconnect and I would received the error message "You did not eject before disconnecting you may have lost data blah blah blah".

I thought a Hard drive had failed this morning because none of them were appearing on startup, so I did some individual tests. Each drive worked fine by itself on this and my other mac (a PBG4).

So I plugged the FW400 drive directly into the FW400 port on the back of the display. That worked fine, plugged the 600mb FW800 drive into the computer. That worked fine, plug in the FW800 1TB drive to the to the FW800 600mb drive. . .the drive stays slient, the other two drives stop responding and then they all disappear. Even Disk Utility can't see them. Now get this, if I unplug the 1TB drive the other two drives immediately re-appear and function normally like nothing ever happened.

This FW800 Daisy chain issue is present irrespective of which actual FW800 drive is plugged into the computer. Same thing happens.

As I said, there is nothing wrong with the actual drives, they all work fine individally. I don't know what to do though, I must have the ability to Daisy chain drives on this port as it is the only FW800 on the system and I use it for editing video.

Does anybody have any idea what the problem could be? Everything worked fine recently and I haven't made any software or hardware changes recently. . .

Your help would be greatly appreciated, thank you in advance.