Why can't I host?

Ever since the switch to the new masterserver, I've been unable to host.
I have no router, and I was able to host before, but nowadays, I even have trouble joining servers. :/
Any suggestions to help me fix this?
I put srb2win on the list of exceptions in my firewall.

Open up config.cfg and put this in :
"ms.srb2.org:28900"

Where it says masterserver.

Didnt help...It was already set to that. D: