Group Policy applied on local system administrator account

I have made the group policy for user based restriction on AD using Windows Server 2003. Everything works fine except that few computers who have local administrator account in the system, group policy has been applied on it including domain administrator account other computers are working fine with policy. I dis joined  the system on which group policies are applied on admin accounts from the domain still the policy restriction is there. We are using Windows 7 professional edition kindly tell me how to solve this issue that in future local administrator account of the systems wont effect. Thanks in advance