BPMN Message (instances) moved outside of Business Process

[Geert Bellekens]

When making an BPMN2.0 Business process Diagram you typically create the BusinessProcess element and have a diagram nested under that element.
Now typically when creating things on a diagram these things are located at the same place as the diagram.
So if I add something on the diagram it will be nested under the Business Process element.

That is true for everything except for BPMN2.0 Messages. They get moved out of the business process to be on that same level.
I don't know why that is, and if there is a good reason for it, but that in itself wouldn't be a big problem for me.

Now because we want to depict Messages on a diagram more then once (we put the message icon next to the MessageFlow to make navigation to the composite diagram of the message easy) we use Message Instances.
I created a stereotype Message for Object as well (with a shapescript that makes it look like a BPMN Message) so our Message instances look like messages. (a script takes care of the composite diagram for the instances)

The problem is that EA moves my Message Instances out of the Business Process element as well.

So please, if possible remove the strange behaviour that moves messages out of the business process.
If that is not possible then at least check the type of the element (Class) as to leave objects alone when moving.

Thanks

Reported as bug.

Geert