I use Smart Security 4. Sometimes when I start Left 4 Dead or Portal I get a firewall dialog pop-up. I use interactive mode. Every time I clicked "remember action (create rule) and allow". The problem is that it keep appearing and it creates multiple rules for the same program. This is how my list looks right now... I cleaned it up a lot of times... http://i264.photobucket.com/albums/ii182/Transsive/tech/ovrl.png I tried custom rules as well (to allow both directions). Still did not help. I don't get any "application has changed" warnings. Today Portal wouldn't start, while the game was loading it kept losing focus to the new rule dialog, and then it crashed. I had to disable filtering to start the game... Now I don't get any more dialogs but I know they'll be back. Edit: Back already http://i264.photobucket.com/albums/ii182/Transsive/tech/ovrl-crash.png Why isn't one rule enough?