I was having drive problems with a USB drive in Ubuntu Linux. It was working just fine, then it started mounting the drive as read only. Looking at the results of mount looked like:
/dev/sdc on /media/50B5-FF5D type vfat (rw,nosuid,nodev,uhelper=udisks,uid=1000,gid=1000,shortname=mixed,dmask=0077,utf8=1,showexec,flush)
I did a file check, and it gave me some errors:
james@bossk:~/scripts$ sudo fsck /dev/sdb1
[sudo] password for james:
fsck from util-linux-ng 2.17.2
dosfsck 3.0.9, 31 Jan 2010, FAT32, LFN
Seek to 499365376:Invalid argument
Looking around online said 'try mounting and unmounting it' and 'try formatting it'. Unmounting and mounting did nothing for me, however, formatting it got rid of the seek error. I have heard things that after so many file read/write cycles, you may get this error. This disk is used constantly, writing and erasing files to it, although this is in subdirectories, not the root. So I still have no idea what went wrong, but formatting the drive fixed it.