L4D and Valve Updates

While I appreciate that Valve are looking to provide some DLC soon for Left 4 Dead, I'd really like them to sort out a couple of things with the game. I mean, we've caned our way through the game multiple times and played an obscene amount of Vs. but how things like the melee and grenade bugs crept through after they went through that hassle with CS I don't know. Wouldn't mind giving the QA team a proper slap! ;)