Comment 1 for bug 498152

What way are you sharing between these computers? From the sounds it would seem that your sharing on a Samba server and it's not through something like a dual boot and sharing on partitions. If you have any sort of error log, that would help a lot. Have you tried to do the same actions (i.e. copy/paste) through terminal commands or has it just been with the graphical user interface?

Zack