PowerBook does not read Ext. HDD anymore after restart from stall

I’ve a Seagate Dual Firewire 400 External Hard Drive. My PowerBook G4 was stalling due to some silly application, so I press the ON/OFF button the restart it while my external hard-drive was still on. External hard drive was not being used at that time as I was planning to eject it and unplug it but my Powerbook stalled, so I restarted the laptop with the Ext. HDD still plugged in. When it came back on up, I didn’t see the icon for my external hard-drive anywhere! I panicked, did another shut down and started the laptop up again. Icon for my external hard –drive did not appear even though the light for it was still glowing. So I pulled out the fire wire, and put it back it. Sill no icon. I pulled out the fire-wire, shut down my laptop and started it up again, then inserted the fire-wire of my external hard drive again and still no icon. Help! What can I do? I’ve got all my files and backup in there!

Thank you! I appreciate all help!