Here is what I found in the error log.
[18-Dec-2012 01:41:08 America/Chicago] PHP Fatal error: Cannot redeclare class HTTP in /home/[company_name]/public_html/mailbox/plugins/password/drivers/cpanel.php on line 40
[18-Dec-2012 02:59:21 -0600]: PHP Error: Failed to load plugin file /home/[company_name]/public_html/mailbox/plugins/jscolor/jscolor.php in /home[company_name]/public_html/mailbox/program/include/rcube_plugin_api.php on line 202 (GET /?_task=settings)
I suspect, the wrong is in the code. But I can't find it.