Hey,
Couple of suggestions that might help. Note this is my experience w/ a 2004 equipped w/Mark Levinson.
1)Try driving around sometimes the rattling of driving for a few days fixes problems with the CD player (at least once for me).
2)Disconnect the battery wait 30 min and then reconnect, this resets the system and forces a map reload from the Nav CD (separate from the Multi-Disc).
3)Cycle between the CDs in the changer (via the screen) or perform a Disc-Scan, anything to provoke movement in the aperture.
Also make sure you are in the CD screen when trying to eject (I don't think it would affect anything but that's where my screen is when I go to eject).
Best of luck!