winXP workstation can’t logon NT4 domain

I’m not sure if this is an known problem.
some user of our company update win98 workstation to winXP professional.I can add those workstation to company’s domain.but after restart,when try to logon to domain.it’s was reported ‘domain controller can’t be found or can’t be connected or somethings like this.
This problem does not apply to all XP workstations.sometimes maybe one XP can logon occassionally,once it logon succesfully,it can work well in the following time.
What’s point of this problem?
Any help is appreciated.