For some reason I have discovered that I can no longer edit any of the data I have on my USBs. I was once able to edit it and I am able to edit the data on it on other PCs. I am running 32 bit 12.10 if this detail is required.
I had this happen to me sometimes, and mostly when I use FAT formatted flash drives.
Can you copy files to it using the terminal, could it be related to this bug?
Most of the times that this used to happen to me, I was able to solve it by plugging it into a Windows machine, and using checkdisk on it (or whatever it was called, haven't used it for a while).
Just realized now, I never tried to use Ubuntu's fsck, and I have no idea why.