[users] Thunderbird reply acting odd?

[RpmForge4Bill]

Using version 1.5.0.12 (20071020) of Thunderbird, when I start a reply 
to  a message, it fills the initial "To:" using the "From" header of the 
original poster rather than "Sender" or "Reply-to". This last seems 
understandable as no "Reply-to" is seen in the headers.

Anyone know how I can alter this obnoxious behavior? It doesn't happen 
on other lists. I suspect a "Reply-to" is needed in the mailman(?) 
configuration of the Rpmforge site.


TIA
-- 
Bill