Strange thing happened when I reinstalled my Business CD head unit after tightening a loose on-off switch. In AM mode, the radio no longer tunes North American AM radio frequencies (i.e. even numbered frequencies), but now tunes odd-numbered European station frequencies. It shows "MW" (medium wavelength) instead of "AM" on the display. So now when you want to tune an AM station, e.g. 1180 kHz, you can only tune odd frequencies (e.g. 1179 kHz). It also has more than one AM mode, which it did not have before. Reception, never great in AM to begin with, is further degraded by the mis-tuning. FM mode, CD player and ICE iPod interface work just fine as they did before removing and reinstalling the unit. I can't find any info on how to convert the radio back to NA radio frequencies. Is this something that the dealer can/must do? Is there some magic code I can enter?