unplugging the changer works less often than it does...in terms of resetting.
i would suggest pulling the fuse to the head unit for a few minutes. fuse
should be in rear panel of the head unit. if you pull battery cable to accom-
plish this, it is likely to reset other memory settings such as seats, mirrors,
windows, roof..... oh, be sure to have radio code available if you pull the
fuse. i've used this technique on 3 E320s (99, 99, and 00) successfully.
anecdotal evidence, i know but hey, it worked.

__________________
-- raymond~
47º 34'N 122º 18'W