I am new to Ubuntu and have a palm pre from bell. I normaly plug in my device with my usb cable and a drive automaticaly shows up on my desktop. then i normaly drag and drop my .mp4 files on to it. recently right after the filetransfert is completed the drive disapears??? i am unable to find a way to disconnect the Pre before pulling out the usb cable. Causing data loss.

can anybody help me please?