I have a web server with SQL express 2008 installed. I was trying to connect to this from my local machine using SSMS. After enabling TCP/IP in SQL configuration manager, starting SQL browser service and opening up the firewall I still couldn't connect using xxx.xxx.xxx.xxx\sqlexpress as the server name.
Finally out of frustration I tried to connect taking off the sqlexpress instance name to just xxx.xxx.xxx.xxx and it worked!
I'm really at a loss here as to why this works. What would happen if I installed more instances of SQL?