Download latest ehcp package (http://www.ehcp.net/ehcp_latest.tgz),
logout of ehcp gui, backup your original files
put files in package in your ehcp dir, except config.php
restart ehcp daemon: /etc/init.d/ehcp restart
login back to ehcp gui (upon first login, some missing table rows will be rebuilt, if any, you may see some "field not found, setting up...." messages)
That should work now.
Similar technique should work for future versions of ehcp.
when ver.0.30 out, upgrade in same way...
I will add all commands here...
(you may look also at http://www.ehcp.net/?q=node/171)