Cannot add Computers to DSfW domain

We have been running DSfW for a couple of years.
Recently we found we couldn't add computers to the domain any longer. Also using the MMC all the existing computers are of type mSDSComputer which the team suggest what is normally there.
Both DSfW servers are running SLES10 sp3 and eDir 8.8sp3

The logs show the following error:
Aug 11 19:00:33 dsfw1 xadsd: [NETLOGON] PC02335$ opened secure channel
Aug 11 19:00:33 dsfw1 xadsd: [NETLOGON] Setting account password for object <cn=PC1234,cn=Computers,dc=company,dc=com>
Aug 11 19:00:33 dsfw1 xadsd: [NETLOGON] Setting account password failed: Access Denied.

Googling didn't reveal much useful info.
Thanks
Simon