I recently had a very odd problem occur on my Mac. After a reboot both of my external drives were renamed in the Finder. My Time Machine drive (previously named WD 3TB) changed to 3 and my external Seagate drive (previously named Seagate 1.5TB) changed to 332. I tried 1) unmounting and then remounting the drives through Disk Utility, 2) physically unplugging and then reconnecting the drives to my Mac mini, and 3) rebooting my Mac. The Finder and Disk Utility both continue to show the names 3 and 332.

Any idea what caused this to happen? I just renamed the drives to their original names in the Finder, but would like to know why/how this happened.