Virtual Users And Domains With Postfix, Courier And MySQL (Ubuntu 6.10 Edgy Eft)

I use that How to in Ubuntu Feisty 7.10.
I can't "dpkg-buildpackage" (page 1). The problem is "libpq-dev" can't be installed, because it depends on "libkadm55" but when I "apt-get install libkadm55", then:

I can't "down-grade" libkrb53 to 1.4.4-5ubuntu3, so now I can't use Postfix-quota in Ubuntu Feisty.

 

If you're using Ubuntu Feisty, I suggest that you use this tutorial: http://www.howtoforge.com/virtual_users_and_domains_with_postfix_debian_etch
because Ubuntu Feisty and Debian Etch are very similar.