Connectiong SQL Server through a firewall

Can anyone help me on this ... we have opened up port 1433 but are still getting the following error :

SMB: R session setup & X - NT error, System, Error, Code = (109)

STATUS_LOGON_FAILURE

SMB: NT status code = 0xC000006D, Facility = System, Severity


Seems like it's trying to do some kind of authentication ? This obviously won't work as the client (VB) application is connecting from another domain. Can anyone offer any suggestions as to what might be going on and how to get around this problem. I'm using the following connection string :


Driver={SQL Server};Server=178.40.45.1;Network
Library=dbmssocn;Uid=ssv;Pwd=12345"


Thanks in advance

Ian.