Try checking the clock and timezone and make sure they are reasonably close (within a minute or two). That should only keep you from logging in once you've joined, but it might preemptively deny you because you'd have an issue once you came back up if you didn't sync the clock.
I've had strange silent fails between domain trusts when the time looked the same, but the time zone was off. The silent fail was seeing zero users when browsing another domain, no big red box saying "dude, clock is off - way off."
This may not the be answer, but it's something to have a look at during a silent fail on credentials.
Also what credentials are you using? Are you a domain admin or just adding them as a regular user? If you don't hit the add limit, you may be seeing an existing computer object that your user account does not have the access to delete - then create. Even though you would have the access to create when joining a fresh machine.