I have just faced the same problem with my brand new playbook and had to perform a forced update for the software and it fixed
You fix it by the following these steps :
Step 1: Open BlackBerry Desktop Software on your Computer.
Step 2: Make sure that the BlackBerry PlayBook is turned off completely.
Step 3: Connect the BlackBerry PlayBook to the computer while powered off.
Step 4: If the BlackBerry PlayBook tries to power on (any LED lights display), keep holding down the power button until the BlackBerry PlayBook powers down.
Step 5: A message should appear on Desktop Software stating that the BlackBerry PlayBook could not be detected.
Step 6: Select the Option "Update" (there is a limited time frame to select Update when this message appears.)
If you do not get the pop up message indicating that the BlackBerry PlayBook could not be connected, please perform steps 1-6 again.
After you have completed the forced update, you will need to go through the out-of-box setup again.