have you messed with your settings?
Sorry to have to ask you this, but do you have a legal copy of cs:s?
Lately, I've been seeing lots of players connecting to servers with illegal/warez copies. Their steamIDs all read STEAM_0:0:0
That's when you know they're not legit. Sorry I had to ask that
The reason I ask is because of that weird message. No password? I've never seen that before. Also, your background looks very different from default. Like it's cutt off on the side. Very weird.
Anyway, let us know. And iss this the first time this is happening?