Sony microvault failure?

I have a 4gb Sony Microvault with some fairly important stuff on it. I've been using it in conjunction with my IBM ThinkPad and other computers for at least a year now with no trouble. Today I tried to send a file there from My Scans and it didn't work. Ever since then, anytime I try to open up the Microvault my computer (as well as my girlfriend's says) "Insert a disk into drive F:". Can anything be done to recover my files or am I just SOL? Many thanks.