When I try to transfer files to my MP3 player my computer locks up. I am currently using Ubuntu 5.10. At first I thought it was the cable, because I was having random freezing problems in Suse 10 and I had just left the cable plugged in all the time, and when I needed to connect my camera or MP3 player I just had to attatch it. I tried to install PC linux and Ubuntu to see if the problem was related to Suse, but they would freeze as well, so I remove my raid card, and tried again, after all it was only $10.00 and I have been using it for a while, so it may have just died, at the same time the usb cable also got unplugged. I had no freezing problems until my wife tried to add more music to the MP3 player and it locked up, except for the mouse, keyboard doesn't do anything, and clicking on the any icons have no effect. So i figured it probably wasn't the raid card and it was the cable we had been using to connect to camera and MP3 player.
This is what I thought until the other day, when the same crashing happened when we tried to use the scanner. The scanner is an Epson 3480, I think. Whats funny about the scanner is that it usually works and I have only experience the lock up with it the once. So it may be unrelated.
My computer has an ASrock 880 upgrade, Athlon Xp 2800+, MSI Geforce 6600gt, Soundblaster Audigy, Realtek NIC.
A little while ago the onboard NIC stopped working so I added the PCI one.
If anyone has any Idea what may be causing the problem I would appreciate the help.

It seems it was a MB issue. My computer started randomly shutting off, but not all the way, the power light was still on, so I tested my ram, video card, and psu, all worked so I replaced the MB and haven't had any problems since.
Thanks for looking everyone.