Many of the zombie survival servers based on MCDzienny are having problems due to the fact that players can press Enter to save a spot and then tease a zombie into believing that they're gonna get him/her until the player presses "r" to re-spawn.
This was blocked in Minemaniacs zombie server, and it shows that they spawn back to the spot but automaticaly brought back to where they were. I hope this can be done, then I would be able to set-up a zombie server without cheaters.