G4 Running Os 10.2.8 External Firewire Lacie Will Not Unmount


The disk was rebuilt with DiskWarrior and checks out ok with new permissions. Coppied with Silver Keeper from onother disk which still works, also external Seagate. When computer shut off, it shuts off. Then when restarted from another drive and turned on, the disk will unmount, but eventually it starts
chattering again for no reason and slows down a bit whatever it is doing. This is a recent drive, so I do not think it is hardware related as the same content was on another drive and that one failed eventually with same simptoms. That one was a Maxtor though, so not brand related problem. Also ran Norton Virus check with latest definitions and nothing was found, but the Norton always crashes right before it completes the whole drive scan so I do not know what is going on. Please help! Thanks.