Error joining ESXi 5 hosts to AD domain

[davema9350]

I am trying to join 10 ESX hosts to my AD domain. I was able to add 6 of them no problem. 4 of them time out after a minute or so with a generic error 'errors in active directory operations'. I have been googling it all day and I am not making any headway.

I've tried joining a domain name with and without the FQDN, I've tried using my domain admin account with and without the \ and @ , (note the 6 that joined successful did not like the \ or @, and worked without it).

All 10 hosts have DNS entries and they resolve correctly. The hosts can ping and resolve the domain name and DC.

I tried disabled the firewall completely.

I cross checked all services and firewall exceptions with hosts that worked and aren't working, no difference.

I'm kind of at a  loss any ideas?

[a_p_]

Did you check whether date/time are correct on the hosts?

André

[davema9350]

Yes I confirmed the date and time are roughly the same (within 30 seconds or so) of all hosts. I will note however that the NTP client is stopped, and there are no NTP servers in our domain. The time is in synch manually though with the DCs and all other hosts.