Domain Listed by Netbios name

I am adding a A.D. based domain to my NT 4 based network. I have created a trust between the two both ways and have a DNS server on the AD domain. I have the AD server in the Native mode. The problem i am haveing is that on the AD server in the logon, only the netbios name of the AD domain is available. I do not know why the proper name is listed ( I.E. abc.xyz.com )