I configured a new Issue Custom Field (with Date format) and I need to filter issues by this field where its value is overdue (less than today). I applied the filter type "more than days ago" with value "1 days" to this field and the query returned the overdue issues and issues with NULL value. I need only the first one, without the null values.

Applying the same filter to a native date field (like due date) the result is exactly the expected (only the overdue issues were listed, without null values).

Related topic on forum - http://www.redmine.org/boards/2/topics/32096?r=37846