With the new 1.4 patch being released just days ago.....many servers are still being patched. The 1.4 patch allows for a new "content check" feature and when turned on(server side), client wont be able to connect unless they have a "pure" install with no mods installed in thier game directory. You could stick to servers that have Content Check enabled to help prevent cheaters. You could also check
http://www.counter-hack.net/ for a list of the "known" cheats in many online multiplayer games and how to spot them and even how to prevent them in some cases. Right now there are 4 "known cheats for BF1942 as you may read about on that link. The TechIMO clan for BF1942, [TIMO], has a couple of private servers we play on provided by members of TechIMO/ClanIMO for our clan practices/stunt videos etc...
There is obviously no completely cheater free server out there. The best thing you can do is stay patched and learn the cheats being used and how to spot them so you are able switch servers when cheating is spotted.
BTW, Welcome to TechIMO