Mouse area fill entire window with drag.target = child small rectangle - when trying to move child rectanlge - if click inside rectangle there is no reaction, no any events, it doesn't move, if click outside it works, it moves etc...
If inside child rect place another mousearea(reason for using drag.filterChildren) - can move child rect when click inside that small mouse area.
Video demonstration included:
1) running on Mac OS X - working correctly: http://youtu.be/degqxZlUc2c
2) running on iPad Air - not working correctly: http://youtu.be/_emPJYb7KdQ

Also if i disable drag.filterChildren it working correcly(can move rectangle if click inside it\outside it etc..), but child mouse area's stops responding to clicks (expected behaviour).

Example of code attached below.