Exactly the same thing happened to me on mine in my Focus mate. The CD's sometimes jam. Take the unit out and and remove the CD's from the unit, as I remember the trays are all on a spindle and you need to just gently move them up as far as they'll go so you can get the CDs out manually. It is possible to do although the last ones will be tight, but like I say take your time and be gentle. Then make sure that all the CD trays are back down where they started, bolt it back together and put it back in the car. All should then be well.