By default selinux doesn't let nfs work (an intentional decision from
the upstream vendor: they figure if you're savvy enough to set up nfs,
you can tweak selinux to allow it).

However, it's easy to change the policy to allow.  Here's a blog post I
googled up while trying to remember the commands involved:

  http://prefetch.net/blog/index.php/2010/11/02/configuring-a-linux-nfs-server-in-a-selinux-managed-environment/

  Alec

-- 
 	    Alec Habig, University of Minnesota Duluth Physics Dept.
	    		    [log in to unmask]
		       http://neutrino.d.umn.edu/~habig/