Better to show example:
This is simple Sprite with Drag and Drop behavior.
Try to drag with mouse and then with touch (developer mode, any phone or tablet simulator)
You will see difference: when exactly sprites is getting new coordinates when started moving.
With mouse it is perfect.
But with touch, cursor (circle) should travel some distance (hope it is half touch radius) until it starts updating coords. You can see how sprite jumps (once in the beginning) when you try to drag it with touch.
Try move as slow as possible to see exact issue.
Touch coords is disabled once you move cursor withing touch radius, even if move a lot (circular movements)
Cannot solve this issue, faced it in few projects.
Thank you for any advice.
Example src file: gamepad.com.au/scirra/TouchBug.capx