"interface not registered" Windows Media Player 9

Can somebody help me?! I've been using WMP 9 with no problems for several months. The past couple of days I have been unable to transfer any files from this (e.g. to my cdrw or pda) and get the message "interface not registered ". I went to web help to be told it was error 80040155 and that "sorry no more help is available for this problem at this time ". Some help! Anyhow, I've had a cursory look on the net and not been able to find anything useful. Any bright ideas? Thanks in advance.

 

I think you may have run into the built in Digital Rights Management feature of WMP 9.0