All,
I've had this problem for some time and just cannot seem to resolve it. I've had steam installed via wine for some time, and the installation works nearly flawlessly. My games (Killing Floor, L4D, etc.) work well single-player, but I cannot connect to any servers. If I pull up the server browser in Killing Floor, no servers appear. If I look at the servers my friends are using in the steam server browser, they all report "server not responding." Steam runs in online mode, though, and friends chat as well as other network features work.
I'm fairly sure this isn't a firewall issue, but I cannot figure it out. If anybody has some input, I would appreciate it.