I was just trying to reproduce the issue, so I was changing my drive labels about, just so happened to land on fart for the duration of this thread ;-). If you right click on the drive in Explorer and click properties the very top field is your drive label. Does this have the old or new drive volume?
Also, you could open task manager and kill the explorer.exe process, which should restart automaticlly to see if that makes a difference. If it does not restart, just click file >> run >> explorer.exe.