Computer Objects created via powershell script not receiving GPO's or updated group membership

This one's got me stumped:

We have a Powershell script that creates an OU, and a computer object within the OU. When I join a machine to the domain using the powershell-created machine account, it does not receive GPO's or update group membership. Whereas, it I manually create a computer object within that OU, and join the domain using that machine account=BOOM - GPO's up the wazoo.

To further annoy and confuse - I see no errors in any event logs corresponding with a gpupdate /force.

I've compared security properties on each account and am not seeing anything obvious. If it helps, I can publish the (de-identified) powershell code.

Any help would be greatly appreciated. I've got nothing thus far.