OS X 10.8.4 - Hard drives and USB drives showing up as numbers, not names.

Question

It used to display as "System" for my main hard drive, and "Media" and "Time Machine" for my USB drives but since recently they only ever show as "57.80", "-263" and "60+000/=76" respectively.
Reboots don't show them as they should be. They appear like this in finder, desktop and disk utility.
Any way to get it so their names show instead?
Thanks.

Answer 1

Back up all data.
Triple-click anywhere in the line below to select it:
{ diskutil list; echo; diskutil cs list; } | open -f -a TextEdit
Copy the selected text to the Clipboard (command-C).
Launch the Terminal application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Terminal in the icon grid.
Paste into the Terminal window (command-V).
The command may take a noticeable amount of time to run. Wait for a new line ending in a dollar sign (“$”) to appear.
A TextEdit window will open with the output of the command. If the command produced no output, the window will be empty. Post the contents of the TextEdit window (not the Terminal window), if any — the text, please, not a screenshot. The title of the window doesn't matter, and you don't need to post that.
If any personal information appears in the output, anonymize before posting, but don’t remove the context.