PB g4 wont mount external hard drive anymore


I have a LaCie Porsche design hard drive, 250 gig, usb 2.0, i only have used it on 2 powerbook G4s, after transferring files from both computers to the hard drive when the laptops were rebooted, the disc stopped being recognized. what can i do ? btw it still comes up on system profiler, but finder will not recognize it , drive will not mount.

edit- I just tried using data rescue, and it did not work
edit- this is what comes up in system profiler
LaCie Hard Drive USB:

Version: 0.00
Bus Power (mA): 500
Speed: Up to 480 Mb/sec
Manufacturer: LaCie
Product ID: 0x0341
Serial Number: 10000E000A039FEB
Vendor ID: 0x059f