Resusage of Subprocesses

Please have a look to the follwing use case:

Preparing the implementation of a webservice based solution I’m currently modelling the expected interactions between process services and low level services in BPMN. To improve modelling performance I decided to compose embedded subprocesses whereever possible, and to define this embedded subprocesses as gerneric as possible.

Switching to new BPMN diagram I define new pool representing some other process service. Next step is to drag and drop the embedded subprocess defined before into the pool. Basically that works, but subprocess every time looses it’s diagram content. Well, diagram content may be reattached by checking the plus symbol at the subprocess bottom line, and selecting “Add existent diagram”. But the major problem with that approach is that all other diagrams where same subprocess is already contained will change there behaviour (subprocess is contained as view, when adding subprocess to another pool it looses content in all views, sequence and message flow will be destroyed).

A) Is there any´thing wrong with my approach to reuse subprocesses by Drag&Drop from model explorer?
B) How to prevent dropped subprocesses from loosing diagram content, so that existent diagrams will not be influenced?

Thank you for supporting - FrankT