It should not display the retail price if it is not less than the product price. I think I might see the problem...
on the page /webassist/plugins/catalog/results.php
Update the line of code (around line 247)
<?php if( (isset($row_MaxMinPrice['MaxRetail']) && ($row_MaxMinPrice['MaxRetail'] != "") && $row_MaxMinPrice['MaxRetail'] > $ProductPrice)) { ?>
to:
<?php if( (isset($row_MaxMinPrice['MaxRetail']) && ($row_MaxMinPrice['MaxRetail'] != "") && $row_MaxMinPrice['MaxRetail'] > $row_MaxMinPrice["MaxPrice"])) { ?>
I think that will solve the issue... you could also just leave the retail price blank if it is not less than the actual price.