Did you disconnect the lead while the cd cartridge was in? I did this once and had to send the changer away to get fixed. The cd that is currently loaded may be damaged in the process. Speak to your friendly ICE shop.
Did you try to change to a different CD?
If not, try it, my cd-changer got stuck once due to a CD-R, I changed to a different CD and it ejected with no problem...
I hope it's that simple for you too!