Seems my server is fouled with users that have zombe installed with more than just fly enabled. Plus other issues that allow for cheating. Right now i use CF Banner to keep the flying and cheating off, but i was wondering what else is out there.
NoCheat, as mrpointyhead already said. ZombeBanner only sends a "hey, please don't cheat" to the client and the client can easily ignore it. NoCheat however analyzes player movement and automatically tp's the player back.