Setting location behaves strange when overlapping with other object

Hi,

say i have a node (actually a group) positioned programmatically by calling moveTo().
it works fine normally. but if the node is overlapping with other object ( a part consists of a polygon shape), after the moveTo() call, the node in canvas is not at the correct place.
is this behavior kind of ‘overlapping avoidance algorithm’ ? how to disable it? i want the node to be at the exact place that i moveTo().