yppasswd error on Nis Master

[Tiziana Manfroni]

I have a NIS Master host on fedora 4.
On Nis Master a user can't change password because has an error :
"yppasswdd not running on NIS master host" (but yppasswdd is up and running)

but user cans use yppasswd from Nis Slave or Nis Client.
The user root cans always do everywhere.
On fedora 2 I dont' have this problem.
Any idea?

Thanks in advance

	Tiziana