I would probably do that first, just create them a new profile, but you may want to check if someone has created a policy, (like I have done on my machines here) where the default logon has nothing on their desktop. If they were created from that, (or recreated if you delete their profiles and try again) it may very well be a policy like that. search for a .POL on the machine, and on the DC. then go through it and make sure.
this particular section will stop unauthorized users from getting in.even if they try to boot it into safe mode. and bypass a domain authentication, it actually works pretty good, but is a hassle in cases like this.
If you don't want to go through all of that then copy one of the other profiles that work, and rename it to the appropriate user.
Good Luck.