Synchronize destroys layout of surrounding classes

[Asperamanca]

I have a class diagram showing a few classes and their relations. After I have taken the time to manually resize the classes, move them to good spots and move the relation arrows where I want them, I "synchronize with source code" for one class.

Suddenly all my layout changes are undone.

How can I prevent this?

EDIT: It's not just recent changes that are undone. It seems all of my manual layout is simply thrown in the bin, and the diagram is completely laid out according to some algorithm.

[Eve]

There's an option for layout of diagrams after source code import.

Also make sure that you save the diagram before you do your synch.

[Asperamanca]

I have the option Tools->Options->Source code engineering->Auto layout diagram on import set to "On new diagram".

However, I was working on an existing diagram, so I don't think auto layout should have taken place.

I might have forgotten to save before importing. A warning in this case would be great.