Acces to SQL SERVER DATABASE

HI We have a a software that works with SQL SERVER, we run the client on a workstation, it connects to the server (windows server 2003 + sql server 2000). This windows server 2003 is a domain controller for mydomain1.com. Now we have a new domain in our network, mydomain2.com. The problem is that when I connect the work station to this new domain, it can not connect to the sql server and the software doesnt works without this SQL SERVER connection. It says that cannot finde the SQL SERVER. can anyone solve this problem? It looks like no big problem but can not find the solution Thanks in advance