Ftrplt, that is correct. What I'm referring when to climb is if the holding pattern or the start of the instrument approach is usually the same altitude as the 10nm MSA and for some reason you are below that. But, personally if I know that I would be in the holding pattern, I'd stay on that altitude.
Dr R - It's for safety reason. That should give an aircraft in trouble ( say having one engine failed and cannot maintain altitude) to go down that low since the MSA will give a 1,000 feet clearance and hopefully rectify the problem or find a solution.
As the ENR says, you can stay in the lower MSA as long as you stay in that sector.
D6