I am getting inconsistent results using. Sometimes it works other times it doesn't do anything.
Then there are times when some references update and others don't.
Sometimes some references change to a number unrelated to any valid page (page 6 when it should be page 27).

How can I insure consistent, correct updates?

You can force an update of cross-references by switching to print preview (click File > Print) and then return to Print Layout view (press ESC).