USB pen drive crashing finder

I have a USB pen drive that i connect regularly to my ibook without a problem but when i try to connect it to my iMac and it starts to mount and then crashes the finder and i end up in a loop of relaunching the finder and then it crashing. Does anyone know what the problem might be or a solution?

I don't know if this will help but I would mount it on the ibook and reformat it. You might also check it out with a utility like TechTool.

Thanks i will try that out