Joining an AD domain / OU in DS 6.9 SP3 is a two step process: Join domain (root) then move to OU. If the user specified by DS doesn't have rights to the root of the domain the join will fail.
Symantec has resolved this issue in the 'DS 6.9 SP3 config.dll.zip' file attached to this KB by making the domain / OU join a one step process. To update follow the steps below:1) Open up the 'Altiris Deployment Server' applet from the control panel
2) Click on the 'Options' button and select the 'Transport' tab.
3) Select 'Automatically update clients'
4) Click 'Apply' then 'OK'
5) Click 'Yes' to restart the Axengine.6) Download and extract 'DS 6.9 SP3 config.dll.zip' attached to this KB to the '<drive>:\program files\altiris\express\deployment server\agents\aclient' directory
7) Autoupdate will download and update the proper config.dll (ia64, x86, x64) file to the remote systems.