I updated to sudo-1.7.2p1-14.el5_8 and then discovered automount wasn't working. On checking the logs I discovered there were problems reading /etc/nsswitch.conf and checking the selinux permissions showed that it now had permissions root:object_r:rpm_script_tmp_t If I run /sbin/restorecon /etc/nsswitch.conf it sets the permissions back to system_u:object_r:etc_t and the automounts work again.
*** This bug has been marked as a duplicate of bug 818585 ***