i would do the following :
1. take out the cd changer fuses in the rear boot panel.
2. disconnect the 2 plugs at the rear of the cd changer (you may have to take out the 4 bolts to get your hands in behind it.)
leave both out for 10 mins, go make a cuppa or something!
re-connect the 2 plugs then re-insert the fuse.
this should help as mine was displaying the same problems and this sorted it perfect
i could only get one of the plugs out of the rear of my cd changer so it may work by removing only one too.