I have been testing ZCM10SP1 on Windows2003 R2 SP2 32bit and I have been having this issue most of the time.
Most of the time means not always.

XP sp2 is installed on a few hp computers in the test lab from the scratch and find them by IP Discovery from ZCC. Those computers' names are Admin001 and Manager001.
I created Registration setting in advance.

* Device Type = Workstation
* Computer Name = start with = Admin
* Computer Name = start with = Manager

After Deploying ZCMAgent to the computers it reboots as it was configured; however, registration never completed, even after 60min later.
If I login and run command "zac register.......", registration completed and the computers are moved to where it should be on ZCC.

The issue occurred in the previous test lab, and now its the new test lab - setup the lab from the scratch.

Does anyone know why this happens?
This happened when I tested ZCM10SP1 last month in the previous test lab.
Test lab means just a bunch of servers and computers only for testing and preparing for the project.