FIRELITE USB EXTERNAL DRIVE WILL not loa

[bobger1]

I have been unable to get my Firelite 160 gb external drive to load on my desktop for time machine. It has been working up till today. I have a new macbook 2ghz intel core duo and 2 gb ddr3 memory. I have tried changing usb slots on computer as well as on the powered hub. all hubs are working. The firelite drive shows up on the system profiler. I have restarted computer many times with no luck. The drive is only six weeks old. MY OS system is OSX 10.5.6