Click on Drag Resize to increase decrease the size of the Some Content area. Below the iframe the resizing goes without problem but within the iframe the mouse looses control. This happens if the mouse is moved fast enough but still not extremely fast. Dragging and the release the mouse button while above the iframe makes the dragging without any mouse button pressed.
http://jsfiddle.net/3JZQt/ I have included the Mootools More Drag directly in jsfiddle to be able to search for solutions.
