Hi Erik,
It seems there are problems with Mailman on common-lisp.net. I sent emails to, e.g., tbnl-devel which were accepted by the mail server but were never forwarded to list members. I've heard about similar problems from other users. See also here:
http://groups.google.com/group/comp.lang.lisp/msg/faa964a13569bb3c
I understand that you don't really have the time to maintain common-lisp.net anymore, but is there a chance that you can look into this?
Thanks, Edi.