In Reply to: you missed the point posted by krod on Sunday, 5. April 2009 at 09:34 Bali Time:
The blanket rule as you call it will probably vary with different airlines as it is the airline who decide how soon they will open THEIR CHECK-IN DESKS so this is the time to look for on your tickets/itinerary,and other planes leaving should have NO BEARING on how long it takes to check in except in extremely rare circumstances where the airport is absolutely chock a block.
Most appear,in my experience,to have gone back to 2 hours after the initial frenzy of extra security checks a couple of years ago,however i have noticed check-in desks being opened a little earlier than the 2 hours on my itinerary but again only occasionally and not all airlines.
Ted