ORIGINAL: Szilard
With the patch, the editor is now looking at \Matrix Games\The Operational Art of War IV\Scenarios folder, rather than \My Games\etc etc.
This applies for opening, and also for saving - no matter where you opened a scenario from. You need to manually browse to the correct folder each time you want to open or save.
I don't see any way of changing this - or is there something in a config file? It's very annoying.
Anyway, deleting toaw.cfg seems to fix this.