Package mc 4.8.3-3 from UP5 has this very annoying bug (I use mcedit all the time):
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=673252
mc 4.8.3-5 from wheezy repos also has the bug. It is fixed in mc 4.8.3-7 which is in sid:
http://packages.debian.org/sid/mc
http://packages.debian.org/sid/mc-data
I reported this before in the UP5 testing thread.

