Unreal tournament crash

Ok i've been playing ut for meny years now and lasy year i got a new doel core system and put vista 64 on and loaded ut no and have not had any problems untill now.... With utdc v2.1
anti cheet program.... I joned the fragnation latters 1x1 tournament and every time i get on the server my ut crashes and only 64 bit os have this happen to them

help send me patch info ect!!! Please