This issue appears in SL3 Preview only. Subsequently, when published in Flash with HTML5 fallback, the screens behave as expected, and as they performed in SL2 preview. However, if published in HTML5 with Flash fallback, they perform incorrectly as documented below:
I found that all of my Drag and Drop screens I had programmed in SL2 that have multiple drag objects for a single target, and that have been converted to SL3 do not work if the "Drop Target Option" is set to anything except "Snap to center". These worked just fine set to "Tile" in SL2.
The behavior of the drag objects in SL3: Click on object and attempt to drag to target box. The object "clings" to the mouse and will not let go, and will not snap into the target.
I have set up a sample file (attached) that displays this behavior.