I am thinking that the issue isn't with the AD OU, but with the SCS installation. If you gave insufficient rights to the RCS user, it may not be able to access the OU and will cause issues. The RCS user will need rights to create objects, etc in that OU.
If you are able to enter by hand the OU path, and are not using the browse button within the AD Integration window, that would be a issue as well. Use the browse button [...] to select and locate the proper OU.
I would recommend uninstalling SCS (Easy) and re installing after reviewing the user account rights assigned during the installation.
Let me know what you find out.
I figured it out, you must be using the acuwizard and creating a profile, instead of using SCS for creating the profile
Within the ACUWizard the AD integration window has two choices, the 2nd choice is looking for a file location containing the ADOU information. It is not looking for the AD path. see below
I recomend using the first option and just browse to the correct OU for your AMT clients