There are apparently a lot of people still looking for the fix on the Zune players that were struck with the tardy Y2K bug.
According to Microsoft you need to disconnect from the USB and AC power source and then wait until the battery is empty and the screen goes black. After that the Zune needs to be powered back up. That should do the trick.
Customers with music containing DRM (digital rights management) will have to do more because the fix will make the DRM coded music unplayable. Those affected there will need to resync their Zune with their computer. Now, hopefully you are back.