I think Tired stacks. If you've done a lot of strenuous work like mining or cutting trees and haven't slept, or haven't slept in a couple days it will take a full sleep to clear each instance of tired, even though you only see 1.
Sorry, I should have clarified that I reloaded to right before going to sleep to try each option. The standard "Sleep" for 8 hours option cured Tired, but "Sleep until morning", which resulted in over 10 hours of sleep did not.
