Hello and welcome to Just answer.com, Super mechanic here. About your vehicle.
There has been a service bulletin for that type of concern. It involves a reprogramming of the radio. The labor is only about half an hour though, (dealer)
Here is what it states.
Bulletin No.: 07-08-44-017
Date: August 27, 2007
with Six Disc CD Changer Equipped Audio System (RPO UC6)
Some customers may comment on any of the following conditions:
The CD loaded in the radio will not play.
The CD loaded in the radio will not eject.
The disc icon on the radio will not illuminate.
The radio displays an "INITIALIZING" message for approximately 30 seconds after vehicle start up.
Do not attempt to play CDs with paper labels on them in this CD player. The labels may warp or wrinkle and jam the CD player mechanism. Refer to the Compact Disc Care and Cleaning procedure (Document ID #(NNN) NNN-NNNN in SI for more information.
Technicians are to reprogram the radio with new operating software using the following procedure:
If the radio has a CD(s) loaded, it will be necessary to reset the radio and remove them before the radio is reprogrammed. Remove and reinstall the radio fuse to reset the radio and then eject the CD(s). If cycling the power to the radio does not allow the CD(s) to be removed, the radio may have another failure that will not be corrected by the reprogramming procedure that follows. Refer to the Diagnostic Starting Point - Entertainment procedure in SI to begin your diagnosis of this failure to eject CDs concern before reprogramming the radio.
Reprogram the radio using the Service Programming System (SPS) with the latest software available on TIS2WEB. Refer to the SPS procedures and the Radio Programming and Set procedure in SI for more information. As always make sure your Tech 2(R) is updated with the latest software version.
Verify proper operation of the radio and make sure that all CDs can be ejected.