Accessing samba across domains

[Rick Day]

We have two domains, both with a WinNT PDC, and a trust
relationship between them.  There are two Sco Unix boxes
in Domain1 running samba 2.0.6.   
I am using "Security=Domain".

I now want to allow a user in Domain2 access to the Sco 
Unix boxes, but I can not work out how to do this.  
I have even set up a user with the same name and password
on Domain1 just to see if I could get it working, but 
with no success.

Can someone give me some hints about how to do this.  

Thanks you
Rick Day