I wasn't sure whether to post this in GPP or here, but this is more of a tech support issue so I figured this was better.
Anyway, I recently got high speed internet, and a new router. So I go to play Steam, and servers show up in Steam, but not when I launch a Steam game. I can't figure this out. I have DMZ set on my comp so I know the port isn't being blocked. PeerGuardian and my firewall are turned off when I look for servers. WTF... I don't get it.

I even tried reinstalling Steam and resetting my router. The only time I got it to work at all was right after I reset my router. I was right in the middle of joining a game and the then it disconnected and couldn't find any servers again. The weird thing is that Steam can find servers when it's just in the client, but not when it launches a game. None of my other games do this, nothing else has a blocked connection.
Help me out here Totse... I want to play Garry's Mod online!!!