Well, I even deactivated my firewall for some tests and I still got "Unable to connect" message a couple of times. I think waiting for a patch is the best thing to do. Strange that it obviously appears random.
This is the first time in over 10 years i have had this type of problem with a game, well since DOS, WTF!
What are the pings that you're reading of the hostname (even after a couple of times returning from menu to browser)? Is your Virusscanner, Internet protector not blocking any signals? If you host a server, does anyone join within the couple of minutes? Is your ISP not blocking any signals.
It doesnt need to be your firewall only!
The exact same error happened to a friend of mine last night when trying to MP with me for the first time.
- We played with his firewall settings.
- We finally just diabled the firewall, bypassed the router, and rebooted.
No luck. We were still unable to connect with the same error message.
Then, based on the comment in the next patch notes, he created a NEW gamespy account. He managed to connect and play with me for several hours, AFTER reconnecting the router and re-enabling his firewall!
Methinks that "old" gamespy accounts might be the culpit of many folks problems. Oddly enough, I couldn't get one of my Gamespy accounts to work, but another one worked fine.