Out of curiosity have you tried Debian Etch ? Yes I know it's not 'stable' yet, but it should be very, very, soon.
Debian stable 3.1r4 Was unable to install on my new HP server, it was unable locate the Hard drive.. Etch on the other hand installed without a hitch and is running beautifully.. Now if they would just get it all finished up and moved to stable so I can put my new mail server into production...
This is the 'recipe' I used for my new mail server
Debian Mail server how-to with Courier IMAP, Amavisd, Spamassassin, ClamAV
And don't forget to configure your hostname properly.. an oversight here landed me on a blacklist within 2 days of putting my new sever in production.. it's always the stupid little things that tend to bite us.. http://www.cpqlinux.com/hostname.html
Was nothing to plug in a web front end for the users.. I actually used Usermin for the web based front end due to some bizarre performance issues we experienced with Squirrelmail on the old server.. could have been a resource issue though since that old mail server was a PIII 550 w/128MB RAM.. my shiny new server is MUCH faster..
Management absolutely LOVES the new webmail front end (usermin), and that they can easily set their Auto-reply or forwarding options from the same interface as well..
What NIC is in your server that Debian doesn't want to recognize ? what does lspci
report it as ? Might be a simple fix to get it running in Debian stable which you already have installed..