I have a 160 GB LaCie External FW Drive. It suddenly started running while I was sitting typing in Word. I went to verify the disk and I got the error you see in the image attached. It said it needs repair, but I haven't had to do this ever and I'm curious what the error is all about, do I risk losing my data if I do repair, what does repairing do, and what else do I need to know about it? The Powerbook I have is about 17 months old and the LaCie is about 1 year old, maybe less.