Reproduction steps (see attachment for visual clues):
1) Create a Use Case diagram
2) Add two packages foo and bar; make sure foo is at top left and bar is at bottom right 
3) Add a use case in foo named ABC
4) Add a use case in bar named XYZ
5) Select the two use case nodes without selecting the packages
6) right click one of the selected use case nodes and select Align | Bottom

Result:
Use Case nodes are moved outside of their package container nodes.

Expected:
Either the nodes should not be allowed to align with each, or the parents should align as well, or the Align tool should
not be enabled.