Hi all, I've been having a godawful time trying to connect (trying both HLSW and ASE) since the big update. It kept on giving me a fatal error about "filesystem dll".
After a bit of a trawl through the steampowered forums I found that it's a pretty common problem, and that you can still connect if you go through Steam's server browser and not a third-party one. So if you've been having this problem lately there's your solution.
Bizarrely, when I went to connect through ASE just now to double-check the error message it worked just fine, but I figured I'd let you all know my findings anyway, just in case.
Thanks Mouse. Heads up appreciated :)