Domain Users Can’t Log on some stations

I have a domain with 1 PDC and BDC, 24 workstations. some users cannot log onto some workstions. My server manager sees the stations as members of the domain. I have gone to these same 8 stations and checked user rights. I can copy a profile to thatstation but then the user only logs in locally rather than roaming. I can’t change the profile back to roaming. Can anyone make any sense of this.