banning people for a unknown cause like the example you give can happen to any of us yes even you.
so i agree with [SOE]No.Mam's about gamespy servers and the BS.
lag is cause by many things the most common lag is.
1 - low-end PC so you have to set all your setting on low if you have a high end PC is recommended setting it on low too to keep it in sync.
2 - your internet connection in many case lag are cause by the router setup and of cause your hosting server and also some programs maybe running in the background that take some of your bandwidth so closing programs that you don't use will help .
3- distance for example if your in Asia and i am in Europe the ping is 250 up to 400 because that is the time is take for it to receive the signal because of the distance.
feel free to correct me if i am wrong.