Windows 2003 SBS

I have a client that has a SBS 2003 and a Windows 2003 Standard server in seperate domains. They logon to the SBS 2003 Server so they can use Exchange and the functions of SBS 2003. There main ASP apps are on the standard windows 2003 server. When they browse to the server they get a error of Access denied The trust relationship between the primary domain and the trusted domain failed. I have read you can not create trusts with SBS. Does anyone have any solutions around this?

Thanks