samba - Nov 2006 - intermittent login problems (netbios related perhaps ??)

i am in desperate need for some help, i am having problems with students
logging in at this school, continually trying / rebooting usually sorts
the problem.

also doing a nbtstat -R and will also allow students to logon most of
the time.

i have noticed that nbtstat -c shows are domain as on 81.4 when in
reality it is on 81.1 , we had a problem with a share that when
accessing would also be redirected to the shares on 81.4 so we disabled
computer browser service (or what ever it was called) on the windows
2003 server this stopped the problem with typing in the unc path to our
main server (sme server 7) and ending up on a completely different
server.

anyone have any ideas on what could be the cause, why could you get the
wrong ip address for a netbios name ?

does the login process rely on netbios names or am i looking in the
wrong place ??

basically ideas for trouble shooting would be helpful, samba logs do not
seem to really contain relevant data :/