kms

I wan't to install KMS Activation on my Testlab. Machines: Vista 5384 Ent. VL editions
I've ran the script as MS Desciribed on one machine with the appropriate code *question: Why is this have to be run on Vista\Longhorn machines? do i have to tell one of my production users that he'll be acting as a KMS Activation server from now on and to remember to kepp his computer running?? why won't it work on 2003 instead? Longhorn is schedualed to be released after vista!
Anyway, while trying to activate the KMS Server through the internet i've recieved what MS says to be an error related to the 25 minimum computer required for KMS - error code 0xC004F038. But this is the KMS Server that i'm installing !
Have anyone else tried this option yet (KMS)?