Memory stick problems

[JohnnyMcKinney]

Something could have gone wrong with it at any point. Try putting it in another PSP or a Sony Camera and see what happens. If it works then, its your PSP. If not, then its no good. The ol' Technician's Way: Trial and Error.

Not likely, he stated others worked in his PSP. Sounds like it's a fake Memory Stick. Those would work for awhile, then just randomly not recognize. See if that's the issue, if not it's probably messed up.