I too have been bitten by this. For as flexible as the Debian Installer is and everything you can do, it's pretty disappointing that it can't do VLANs. A lot of enterprises use VLANs, and it seems it would be important to have VLAN support to install Debian. It's no fun to reconfigure the network just to install/reinstall.
Thanks, Robert LeBlanc Life Sciences & Undergraduate Education Computer Support Brigham Young University
