Can't log on to Windows 7 desktop using network accounts, Zentyal 3.0

[steven-NAB-klein]

I've inherited a tiny Zentyal 3.0 network. There are 3 PCs, all running Windows XP.

I'd like to move them to Windows 7, and I prepped a new PC, and was able to join it to the domain, but I can't log on using a network account. (I can only log in to the Windows 7 PC using the local admin account I created when I first set it up.)

When I try to log on using my network account, I get "The user name or password is incorrect."

I have no problems logging on to the old XP boxes using that same network account.