what really works for us:
1) do the mapping first! map all the elements needed manually and disable automatic mapping as this will screw your mapping.
2) check the mapping criteria for each item carefully. the criteria has to be unique so that the element will always be found. we use idstr or objectidentifier as often as possible (developers can set the value) or of this is not possible, select a unique label or similar stuff.
3) use extended find for all mapped elements that have you have mapped as in 2) and remove all other stuff in between (like .panel, .cell, .table,...), which can change all the dtime.