Instead of the 2.4.1, I loaded the latest snapshot build (ossec- hids-100809.tar.gz) and applied it as an "upgrade". It's working as expected now (I see the md5sum string showing up in the client version) -- hurray!:
OSSEC HIDS agent_control. Agent information: Agent ID: 001 Agent Name: sectest200 IP address: 10.196.2.89 Status: Active Operating system: Linux sectest200 2.6.18-128.el5 #1 SMP Wed Dec 17 11.. Client version: OSSEC HIDS v2.4.1 / e7533a51bf572530456f5c0a2ffbd304 Last keep alive: Thu Aug 12 22:58:28 2010 Syscheck last started at: Thu Aug 12 19:50:28 2010 Rootcheck last started at: Thu Aug 12 19:46:16 2010
