[Pkg-mailman-hackers] Bug#363551: mailman updates itself with every apt-get upgrade

[rjpp at mega.ist.utl.pt]

Package: mailman
Version: 2.1.8rc1 <-this is the version outputed by  
/usr/lib/mailman/bin/version

#apt-cache showpkg mailman
...(etc)...
2.1.7-2.1.8rc1-1(/var/lib/dpkg/status)
...(etc)...

#apt-get upgrade
Reading package lists... Done
Building dependency tree... Done
The following packages will be upgraded:
   mailman
1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0B/7995kB of archives.
After unpacking 0B of additional disk space will be used.
Do you want to continue [Y/n]? y
Preconfiguring packages ...
Looking for enabled languages (this may take some time) ... done.
(Reading database ... 35433 files and directories currently installed.)
Preparing to replace mailman 2.1.7-2.1.8rc1-1 (using  
.../mailman_0%3a2.1.7-2.1.8rc1-1_i386.deb) ...
Shutting down Mailman's master qrunner
Unpacking replacement mailman ...
Setting up mailman (2.1.7-2.1.8rc1-1) ...
Installing site language en ............................................ done.
No updates are necessary.
Starting Mailman's master qrunner.

Now the thing is that if I do apt-get upgrade again mailman will  
upgrade itself again, which seems to me like a bug. I think that when  
he sees that updates are not necessary it doesn't upgrade the version  
or the version isn't correctly stated. Anyway it seems the package is  
inducing dpkg in error.