I have it on good authority that one of the leading causes of lag and general server weirdness is OVERRIDES.
I've been chatting with Barry_1066 today, who is the CEP team lead. His PW (Annakolia) bans override use. His PW is huge, and is extremely sensitive to such things.
In particular, he states that animation overrides can really confuse the server, and so cause problems for everyone playing.
Therefore, if you are having lag issues, please empty out your override folder and restart your client, and see if the problems improve or go away.
