MCX settings

I am having continuing troubles getting my OS X Leopard computers to take on managed settings from Leopard Server WGM. At the moment my lab of G5 iMacs running 10.5.2 will take on any settings that I assign to the computer group. They do not need to be binded to the directory for this to happen, but binding still works. I have numerous labs of Intel iMacs which will not bind to the OD server. They put up a message along the lines of invalid credentials which is not true. If I add them to the computer group without binding them the local accounts will be managed correctly by the server, but any network accounts will not. To make things more confusing - on the Intel iMac I created an image on, it appeared to be applying the managed settings to network and local users correctly, but since deploying the image this has failed. The only difference between the computer I created the image on and the G5s, and the Intel labs that aren't working is that the Intel iMacs have a Windows XP partition and are using Bombich's BootPicker at OS X startup, but I can't see how that could affect things. Is anybody experiencing similar issues? This is driving me insane as I can't set up the computers correctly with printing, web access, application access and it is messy in my setup to manage these settings on a group or user basis.