gdm probs with NIS

You will most likely get a prompt for each user you try to log in saying something like this:

Authorities for file ~/.dmrs is not 0644... will not be able to save...

The text is misleading, and setting the file with the given permission bits will not help.

What seems to help is if you set your ~/  to 0700 and ~/.dmrc to 0600.

Try also experimenting with the file /etc/gdm/gdm.conf. Look up the lines:

# 0 is the most restrictive, 1 allows group write permissions, 2 allows all
# write permissions.
RelaxPermissions=0

Setting RelaxPermissions=1 might help...