A family of Microsoft relational database management systems designed for ease of use.
Thanks for clearing that up.
If you are saving the layout regularly, that's about all you can do to preserve it.
I'm also curious, while I'm thinking about it. And this really is just curiosity. How often do you need to change the diagram in the relationship window? When designing a new relational database application, most of us properly visit it a lot, but seldom after the application goes into production.