I think the Context Window is a great idea, but in practice it is completely non-trivial to implement because auto layout of a cyclic non-directed graph (complicated with directionally biased FactType nodes) is a non-trivial problem. There are unfortunately a number of other higher priority areas right now, but if you have a true crash scenario please send me the model. I don't have a problem switching generations. You haven't corrupted the .ORM file.
Having the context window open in a large model can cause major slowdowns, especially with generations above 1. I don't have a repro case where it crashes outright, it just takes a while to come back. There are other problems with the window (the designer refuses to show a horizontal scroll bar, and selecting an item that is already display in the context diagram does not recenter and refresh (you've noted this above)).
For navigating around a model, I generally us a combination of the Verbalization Browser and the Diagram Spy window. Make sure both are docked so they are simultaneously visible, then select an Object Type. The Verbalization Browser shows a list of Fact Types, where any FactType text and ObjectType text is hyperlinked. By default (toggled by a button on the Verbalization Browser toolbar), the hyperlinks center the Diagram Spy window on a shape for that object. If a shape cannot be found, then the element is selected in the Model Browser. This action is essentially instant because you're looking at a view on an existing diagram instead of creating a new potentially huge diagram from scratch. This is also mentioned in the 'General Use' section of the readme.htm file included with the downloads and installed in the C:\Program Files\ORM Solutions\ORM Architect* directories.
I would eventually like to leverage the extensive work done for the diagram spy window (diagrams with full editing capabilities do not natively live in tool windoow) to enhance context window behavior, making items selectable and editable (with the possible exception of not allowing new shapes). If anyone knows a layout expert who wants to tackle this problem please let me know. What we have now is little more than a proof-of-concept.