Sounds like the inertia lock mechanism may be prone to developing some sort of defect. If that happened with me, my first instinct would probably be to monkey with it.
Let's say for the sake of argument that I got it to start releasing. The next question I would then ask myself would be whether I could then count on the mechanism to operate when I really needed (IE: in an accident).
That said, I would be curious if anyone has specific experience / knowledge with this..
'08 E-150, std roof, wb, 2wd - basic cleanup done. Working on rough layout of 'furniture'.
Pretty much everyone will step on their 'willy' once in a while.
I usually make it a point to stop and put on my golf shoes first..