A small but annoying thing had started to happen to your deployments of Windows 2008 R2 vms in our production environment recently. Whenever we deployed a new vm and used our pre-saved customization specification the vm would be deployed as expected except that it did not join the new vm to our production domain.
The image would be customised, the server name changed, IP settings applied, administrator password set etc but it would no longer join the vm to our windows domain.
Alarmingly, although the option was set within the specification there were no errors recorded for this in the logs on the newly deployed vm (these can be found at c:\windows\temp\vmware-imc\guestcust.log) which I would have expected.
The answer it turned out was very simple. The customization had been modified to have domain\username in the username field of the domain customization properties. Although this looks perfectly reasonable to have in a windows environment this actually needs to be just the username of the domain account which will be joining the vm to the domain.
After changing the pre-saved customization to just the account name and re-entering the password I fired off a test deployment and voilà, 1 windows vm deployed and sitting on our production domain as before!