Plutonium

Hello everyone. I'm writing this because I have problems loading zombies games on Plutonium (T4). Basically, when I select a server from the Server List it will show me the loading screen with the name of the map, but it just won't load. Then I have no choice but to close the process from the Task Manager. By the way, I have no problems loading the WaW multiplayer (not zombies).
Can anyone help me? Thank you in advance.