samba domain problem

[anelephant]

Hi, I have a samba domain where I have 2 xp machines and a windows 2003. One of the xp machines is working like it should, however the other one can't access the windows 2003 server. The xp machines have both been set up in the same way, and the samba pdc is almost identical of that described here:
https://help.ubuntu.com/8.10/serverguide/C/samba-dc.html

I really don't know where to start about fixing this one so any help would be great.