Created attachment 1084655 [details]
Unpinning of elements inside a swimlane

Description of problem:
If you have two swimlanes and try to move some elements inside first of them and whole second swimlane - selected elements from first swimlane will be unpinned from first swimlane (see attachment). 

Version-Release number of selected component (if applicable):
6.2.ER4

How reproducible:
always

Steps to Reproduce:
1. Create business process with two swimlanes and some elements in it
2. Select some elements from one swimlane and whole second swimlane
3. Move second swimlane

Actual results:
First swimlane will lose all selected elements. (see attachment)

Expected results:
All elements which was inside the first swimlane and stay there after moving will stay inside the swimlane.

Additional info:
Related bug 1230212