I don't know if I'm imagining this, or not, but it feels as though it is required to tap slightly above the item you want to select. By slightly I mean perhaps 3-5 mm above the center of the item.

Might be only when trying to pick up items from the ground. Not e.g. in the inventory.

tested device: Samsung Galaxy S, Android 2.2.

Movement and attack buttons appear OK, but you are correct, dragging Healing potions to the 4 item boxes appear to be offset by almost the diagonal size of the item boxes, (down and to the right)

And when dragging Potions from inventory to these 4 quick-buttons is very problematic because you really can't see them.

Thanks

Chief