Just had a scrim with my team tonight and the whole time the server was showing 8/12, even though there was 10 people in.
Were you seeing this in "rcon status", HLSW, or the Steam browser?
Also, there's NO traffic on my public server, and I'm pretty sure it's not even showing up on the master list. John, you have any thoughts on what might be causing this?
For our normal game servers, I haven't seen a server not show up on the master server list in at least a few years. The only thing I an think of that would cause it would be the firewall -- are you absolutely sure that you have all the ports open? Valve games need quite a few ports open, both UDP and TCP. (If you're not sure, you should try without the firewall to see if it shows up with that configuration.)
I actually recommend running without a firewall: viewtopic.php?f=44&t=4025