couldn’t get some win2k back into domain

Hi, i was having problem to have some of the win2k workstation in my office to join back to my current domains, when I am trying to do so, it pops out an error saying that some credential criticals or the domain could not be found. It was weird coz others win2ks and win 9x or XP are joined in my domain happily. I did thought of cabling problem but i still can ping that domain server… so does anyone have any ideas on this???