>> Even if clients were using different server names that resolved to different IPs there could still be network issues with this approach. SQL Server Browser is not always able...

You were correct on all points opc, thanks. 🙂

I did set up an Alias that specified the individual IP address on port 1433, turned off named pipes on the instance,...

Forgot your last question. Yes the Browser Service is running. I believe it needs to be, even when using the default port when you have multiple instances. There are also...

>> Please elaborate on "it does not work"...from where? Locally or from the client? Using what connection details?

Locally on the server I can connect to the instance with any of...

I found that select count(*) and select count(1/NULL) both showed the same execution plan and took the same amount of time.

Dan