See the sample overview window map - when panning in the main map, the overview window rectangle re-centres within on the overview map, which pans to accommodate this, after each map extent change.
Is it possible to disable this, and firmly fix the overview map's extent? This would mean that the overview rectangle moved around within a fixed overview map, which itself didn't pan.
I'm assuming that the answer is no, and that I'll need to create two separate maps and link them manually - but I thought I'd check first to save time.
