Mac Cannot Login When AD Computer Account Is Moved

As above. Macs are bound to AD with the computer account being created in the default container (CN=Computers,DC=DOMAIN.DC=COM). If the Macs Computer Account is moved the Macs cannot login, (for example, (CN=Macs,CN=London,CN=Workstations,DC=DOMAIN.DC=COM) I've not seen this behaviour before so ned a little help troubleshooting. All clients are on 10.6.7 & domain is win 2003.