Win2kPro – Netlogon service not starting

NT4 Domain with mix of NT4 + Win2kPro clients.
Win2kPro (SP1) clients have Netlogon service set to startup automatically, but the service refuses to start – this means that logon scripts aren’t being processed and roaming profiles aren’t being updated.
I have tried to set the service to restart on 1st, 2nd + 3rd failure to no avail.
Can anyone suggest a permanent remedy?