Problem with optional values...

nothing is optional, although it is checked. I am using search and between values. I have tried to supply between values that are bigger and smaller than any in the database to see if that could have been it - and it didn't change anything. Here's an output of the search query with "optional" checked for search and between price values:

SELECT node.nid AS nid,
   node.type AS node_type,
   node_data_field_sale_price.field_sale_price_value AS node_data_field_sale_price_field_sale_price_value,
   node_data_field_sale_price.nid AS node_data_field_sale_price_nid
 FROM node node 
 LEFT JOIN content_type_mlslisting node_data_field_sale_price ON node.vid = node_data_field_sale_price.vid
 WHERE (node.type in ('mlslisting')) AND (node_data_field_sale_price.field_sale_price_value >= 0) AND (node_data_field_sale_price.field_sale_price_value <= 0)