/etc/xinetd.d/rexec provided by the rsh rpm (rsh-server-0.17-2.2.i386.rpm)
incorrectly configures xinetd to start in.rlogind instead of in.rexecd.
fix/workaround: (if you haven't figured it out already :))
change the 'server = /usr/sbin/in.rlogind' line in /etc/xinetd.d/rexec to
'server = /usr/sbin/in.rexecd'
rexec should then work as expected, provided that it is enabled.
*** This bug has been marked as a duplicate of 18107 ***