Guest customization > Join domain fails

Hi,

I am trying to customize a Win2008 R2, renaming and etc. works, but DomainJoin fails.

These are the suspicious lines from c:\windows\panther\unattendgc\setupact.txt:

2012-03-20 15:16:06, Info         [DJOIN.EXE] Unattended Join: Joining domain [intra]...
2012-03-20 15:16:06, Info         [DJOIN.EXE] Unattended Join: Calling DsGetDcName for intra...

2012-03-20 15:16:09, Warning  [DJOIN.EXE] Unattended Join:  DsGetDcName failed: 0x54b, last error is 0x0, will retry in 5 seconds...

<repeated many times>

2012-03-20 15:23:05, Warning  [DJOIN.EXE] Unattended Join:  DsGetDcName failed: 0x54b, last error is 0x0, will retry in 5 seconds...

2012-03-20 15:23:10, Error       [DJOIN.EXE] Unattended Join: NetJoinDomain failed error code is [1355]
2012-03-20 15:23:10, Error       [DJOIN.EXE] Unattended Join: Unable to join; gdwError = 0x54b
2012-03-20 15:23:10, Info         [DJOIN.EXE] Unattended Join: Exit, returning 0x0

First I thought that the machine was unable to reach the network while joining. But I can ping the machine in the time period when log-lines say.

All firewalling are disabled. I've tried to add both the short and fqdn to hosts and lmhosts files, without better results. I've tried using the same user+pass and manually joining the domain after a forced customization and that worked, so its not a permission problem. I've tried using both "ORG global" and "VM local" domain join specification, with the same issue.

Any good ideas?