firewire problem

i'm using a g5 imac. all was well but tonight my firewire ports have stopped working properly. when I plug my ipod or lacie drive in they respond (lacie fires up & ipod starts charging), but the devices aren't recognised; i.e. can't see my drive or update ipod.

any suggestions?

I ran a herdware check and it says my logic board is fine...

help!!!!

Do you have an iSight connected to your iMac? If yes, that causes the problem...
When the iSight is connected to my Mac, I can't sync the iPod, nor really use an external firewire drive, as it disconnects itself after a short while.
After Googleing a lot, I've found out that the iSight causes that trouble a lot...and when I disconnect it, no more problems with neither iPod nor external HD. They can even be connected at the same time.

I wonder why that still hasn't been fixed by Apple, as the problem is known since a while already.