I ran across an issue that were able to debug in the channel today. If you select "Unlimited" in a filter and have anything selected in either the Organization tab or the Location tab, unlimited appears unchecked after the form submission. It's not until you remove those selections, does it revert back to unlimited. Perhaps, greying out those tabs when selecting unlimited (or greying out unlimited when anything in those tabs is selected) would be less confusing to the user.