What do other Mozilla users see?
I'm using mozilla 1.7.2. In the message window I see a normal-looking email with the poster's mail signature followed by the list mail signature. The "attachments" box for the message shows two attachments, namely:
signature.asc (which is the application/pgp signature for the message), and Part 1.2 (which is the list mail signature, text/plain)
The main body of the message does not appear in either attachment.
Paul.