Filter values disappear, form 6000 Dispatch Board

Found this bug when building a custom form with filters, like the standard form 6000 Dispatch Board. - Apply a filter that results in no records - Deactivate the form/window (eg. by focussing on another form) - Activate the form again, the filter values disappear. They are still there, when activating the filter field, but disappear when activating another field. Can this be solved by programming or is this a known issue ?