managed preferences for AD users

Hi everyone. Hope some one can help I have just installed a Mac server that will be used to store art staff and students work. Will also be used to hopefully manage preferences for minimacs that students log on to. I have integrated all the mini-macs into AD and also the Mac Server. I have set up a new computer list and added a number of mini-macs(mac addresses) to this list.Have set up several managed preferences, ie put dock on the right and to remove all items from the dock except safari,and one or two other applications. When I log on to the network I am authenticated by the active directory, my windows home directory is mounted and the dock appears on the right of the desktop.But all of the default icons are in the dock, not the ones I wanted there. If I log on to the same machine with alocal account, not an AD account all the preferences are applied.ie dock on the right,only the applications in the dock that I stipulated. This is driving me mad. Would appreciate any help thanks