My stock CD player/changer locked up too, between disc3 and 4 changeover. very annoying, turning off/on the car while pushing the eject button seems to work!
Another trick that seems to work well, is to eject the whole unit from the dash, and insert a quality aftermarket head unit, that is actually, ''Satellite-Ready''!!!
i have the same problem if there is a sticker label on there... just use a business card (paper of course) and slide it in (still holding the end dont stick it all the way in there) over the top of the cd and press the eject button always slides right out for me!
this happened to me recently, listening to snoop doggs blue carpet treatmeant. i pressed the eject button it looked like it was stickin its tongue out on me. i kept pressing the button. switching back to radio and back to cd. then it came out. and yeah i do smoke in my car, heavily. is the nicotine resin making it all stuck boom??