Plugin.php Error

Hi guys.

I’m getting this error:

Warning: call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, ‘define_queryable_custom_fields’ was given in /shared/web_data1/clients/tahititravel.com.au/vhosts/www/htdocs/wp-includes/plugin.php on line 405

I had the plugin Queryable Custom Fields installed. I’ve tried to delete it, reinstall it, you name it but nothing works. I have also tried to deactivate all plugins through trail and error no luck. Any help much appreciated in getting rid of this error, thank you.

Site is http://staging.tahititravel.com.au

[img]http://i52.tinypic.com/8wckjs.png[/img]