I have a problem with my Sony head-unit/changer combination. When you are playing a CD, the unit suddenly stops playing the disc, bleeps, and flashes 'RESET' on the screen. It only does this in CD mode - radio and tape are fine - which leads me to believe it's a problem with the changer rather than the head unit. The head unit is a XR-C450RDS. The changer is a CDX-70. Has anyone come across this problem before, and if so, is there a fix, or is my changer FUBAR?