How much thumbs up required to get to great Karma?

Karma dropped this morning due to deserting (game completely froze on me; tried closing app and rejoining but the map was still frozen in place), and I haven't been able to get it back up. I usually get it back up to great after 3-4 "honors", but even after 6 "honors" in a row today I'm stuck in good Karma. Any explanations?