If it is a roaming profile I would try resetting the profile.

I had a strange occurance like that. For some reason a user couldn't log in. We are using roaming profiles on a single domain it is rather simple. However, she couldn't logon at all. I changed the password and Everything and still nothing. So I decided to backup here profile (her settings and such) delete the account and re-enter and import back the data and viola it worked. This might be able to help ya. Remember to backup the user preferences.

- MilitantEidolon