Lacie pocket drive on G5

My Lacie pocket drive has stopped mounting on my G5, I've figured out it must be a problem with my mac as the pocket drive mounts on the other macs at work and on my mac at home, so far I've repaired the permissions on my mac and restarted but still not mounting the drive? I'm running OS X 10.2.6. Any suggestions?

Cheers

Edit - Forgot to mention I am conneting via firewire

try connecting another firewire device to the same port, if that device won't work either, your firewire port is dead and will need replacing. if thats not the case, connect it to another mac and reformat it again as hfs+(mac os extended with journaling.)
also, chech in system profiler if there's even a connection being made.