hostname: Unknown host

[DiXeoN]

Heya.

I got some problems here installing RC7 on Debian Lenny!

This is what i get when i want to run the install script:

Quote: Welcome to ispCP '1.0.0 RC7 OMEGA' Setup Dialog.
This program will set up ispCP OMEGA system on your server.

Next you are asked to enter a "fully qualified hostname" (FQHN).
For more infos read http://en.wikipedia.org/wiki/FQDN.

hostname: Unknown host
ERROR: External command '/bin/hostname -f 1>/tmp/ispcp-setup.hostname' returned '1' status !
main:/var/www/ispcp/engine/setup#

What the hell?