Memory Stick Error - USB Device Not Recognized

I recently purchased an LG 1 gig memory stick. It has worked fine over
the past few weeks. It was recognized on my work computer, my desktop
computer and my laptop.

Yesterday I used it to save a file on my laptop. I went into work and
tried to access it (has worked on this computer many times already) and
I got an error that it wasn't recognized.

I got home last night and tried it on my laptop again (worked fine
earlier in the day) and it wasn't recognized. Tried it on a friends
laptop and my desktop, no luck.

What is the deal!?