trust

We have a win2k active directory server with one domain. A xppro workstation is a member of the domain and can map drives to the domain server. A win2k pro worstation is a member of the same domain and can map drives to the server. However when the xppro tries to see assets on the win2kpro we get “trust relationship between this workstation and the primary domain failed”. Both workstation users login on their local machines as “administrator” – is this the problem – should they log in as a domain user? If so, how can we keep their currents programs and desktop settings?