Good news, everyone!
We've finally fixed the cape mod - in theory anyway. The updated version is available on our mods page, right where the old version was.
We're still running 1.3.1 due to FancyGUI not updating, so if you'd like you can install the mod manually using this zip file. I believe it only requires mod loader and minecapes.
Now go kill some zombies!
Lord Commander of the Night's Watch