That error usually happens if most of the PCMS tables already exist in your Database, but there is no wa_settings database.
use the following SQL to create the wa_settings table in your database through phpMyAdmin.
CREATE TABLE `wa_settings` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(50) COLLATE latin1_bin DEFAULT NULL,
`type` varchar(50) COLLATE latin1_bin DEFAULT NULL,
`options` text COLLATE latin1_bin,
`value` varchar(255) COLLATE latin1_bin DEFAULT NULL,
`grp` varchar(50) COLLATE latin1_bin DEFAULT NULL,
`subcategory` varchar(50) COLLATE latin1_bin DEFAULT NULL,
`cond` varchar(255) COLLATE latin1_bin DEFAULT NULL,
`description` varchar(255) COLLATE latin1_bin DEFAULT NULL,
`variable` varchar(50) COLLATE latin1_bin DEFAULT NULL,
`weight` float DEFAULT NULL,
`spry_args` text COLLATE latin1_bin,
`spry_error` text COLLATE latin1_bin,
`help_text` text COLLATE latin1_bin,
PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=7 DEFAULT CHARSET=latin1 COLLATE=latin1_bin