The mailing list for listmasters using Sympa

[address@concealed]

I inherited an installation of Sympa (it's 4.1.1) and it was running
beautifully for well over a year, until I got my hands on it yesterday. I'm 
new
to this, and I've been poring over documentation and lists and google, but
can't figure out what I did.

All messages to all lists are now being sent to the msgs/bad spool, and a
message is sent to the poster saying:

Command not understood: ignoring end of message.
No command found in message

The only thing I remember changing for certain is the sympa.conf (bad, I know,
bad bad bad) and I didn't think to back it up first (also bad bad bad). But I
only changed the listmaster address, via ssh, and I changed it back and then
restarted sympa, but with no luck on the problem.

The installation is on a cpanel server with Red Hat Enterprise and Exim, if
that makes any difference. Everything else seems just fine. List moderators 
and
owners can configure lists, and subscribers get their information and
passwords, and archives are accessible. It's only new message delivery that
I've ruined.

Any ideas what I might have done and what I can do to correct this? Will
upgrading help, or should I correct the problem first, and then upgrade? I'm 
at
a complete loss, and would be grateful for any help or pointers in the right
direction.

Thank you!!