Another Error 26

Trying to connect to a remote server and it errors out witht the standard error 26 - Error Locating Server/Instance Specified)

I've check surface area configuration and tried enabling TCP/IP & named Pipes.

Checked in the browser to make sure it's running. I have 3 instances running on the machine. I can connect to the default instance, but there is an instance i93\microsoftsmlbiz which fails. The instance is using dynamic port 2500 and a netstat -a on the server shows it's listeing.

However on the remote computer when I try to connect through the management studio, in a sniff, it never tries to connect to the correct port. So it connects to 1433 but never tries to connect to 2500. Of course if I try it locally everything works. Again, I've enabled remote connections using TCP/IP and named pipes. I've enabled shared memory, named pipes and TCP/IP.

Any other ideas This is SQL Development edition.