linux nis server - solaris 2.8 nis client login issues

[niraj gupta]

hi

i using latest debian unstable release working as nis server
on solaris 2.8 nis client all of this works

ypcat  <map name>
su - <username>

but

login <username>

does not work

i cannot see any error messages on the solaris, nis seems to be working fine,
any ideas on how can i fix this.
on the solaris box
the nsswitch.conf is ok ie has entries like
passwd       files nis

the pam.conf is default
there is no error message on the solaris box as to why is this failing

earlier the linux box was configured with md5 for passwd, which i have 
changed to standard method

any ideas will be greatly appreciated

cheers
niraj gupta