GUP - Group OU issues

Hi, We are running SEP12 RU6MP1 in our environment. Our SEP infrastructure synch with AD. AD synch is set to occur hourly. When configuring GUPs, we move the machine to be configured as a GUP to a certain OU container in AD. The machine moves to the correct OU in AD, but on the client, it stays on another OU.

I have created a package pointing it to the correct OU, installed it on the server. It seemed fine. After some time, the client SEP group moved back into the incorrect OU container. What might be causing this issue?

Thanks in advanced,

Mabunda