I had the same issue on my 2007 x5. I bought a new dvd drive from Garry Romani (parts manager @ BMW of New Port) for $96 plus a refundable core charge of $137. It was fairly easy to replace once I got the ccc out of the vehicle.
He offers parts at a fairly significant discount to E60.net members (I have a 5 series as well)
Part number is
DVD player 65839273195.
Send him an email @ [email protected]. Ask him for pricing on this part number. Put E60.net in the subject to get the discount.
Good Luck