You can play and not get banned for having a positive score? I'm not coming on here to brag about positive scores/ratios or anything, but seriously, it seems that if you manage to keep your ratio above 1 you must be hacking and you either get kicked or banned. The community seems to have gone downhill if this is the way its going to be ran now..
It does seem to happen occasionally. I was banned recently on an assault server for being too good. If you can contact the admin you may be able to get reinstated. That server must not have been running very long if only 1:1 ratio players can play.