Computers not managed when bound, only when unbound

Hey all, This has been giving me headaches for months. I have three Intel iMacs in this network. They all need to be managed by my Xserve. When I set up their Directory Access, I chose to bind them to the Xserve's directory. They would never be managed, and no amount of mcx_cache obliteration would fix it. I finally went and unbound them and lo and behold they are managed. Am I going crazy here, or should this not work at all?