Resizable: can be moved when grid option is set

When using resizable() without using draggable(), I would expect that it is impossible for the user to make the widget move.

However, when using the grid option, this is no longer the case. As my demo jsfiddle demonstrates, you can make the gadget move by dragging the west handle all the way to the right or the north handle down.

Note that this does not happen for every grid size (in the example, 50 is broken but 80 is fine), and never happens for the east or south handles.

My production system uses jqUI 1.10.3 with jQuery 2.0.3, the jsFiddle uses the same jqUI version with jQuery 1.9.1 because that was the version used on the jqueryui.com resizable() demo page.