Since I knew that one thing the OptimizeN900 script did was to kill hildon-desktop and allow it to restart, I was certainly glad I'd enabled its power button menu item. Easy to click the top button in portrait view -- even if the button doesn't line up with the resistive digitizer I know where the top of the display should be. Getting to the terminal -- or any given application -- is tricky with the scale translation problen.

Since it usually -- but not always -- happens on cold start, rarely happens on "unexpected reboot" and never seems to occur when restarting hildon-desktop by killing it, I have to wonder if a race condition problem exists. Not as in a "man's inhumanity to man" thing, but the order that tasks and processes start and finish under different circumstances. Will try a cold start with keyboard open to see what happens.

If I find out anything else interesting, I'll post. Thanks all for the ideas.