In case you have disabled ipv6 on an SL6 machine, then you need to be 
aware that the recent update to nfs-utils introduced a bug on those
systems.  It has been reported:
   https://bugzilla.redhat.com/show_bug.cgi?id=765909

and nfs-utils needs to be downgraded until there is a fix for this.

Otherwise you will find hundreds of little core files in the root 
of the filesystem ..

cheers, etc.
   Denice
-- 
deatrich @ triumf.ca, Science/Atlas         PH: +1 604-222-7665
<*> This moment's fortune cookie:
I bet the human brain is a kludge.
 		-- Marvin Minsky