Has happened again to me just now too. I've noticed now, that though you can't see it taking during the edit period it often seems to take later. Hope it's fixed as i hit it yesterday a couple of times too.
It's like there is a little guy sitting inside somewhere saying, be careful before you post because if you try to update you're not gonna be able to see if it takes or not before your editing time is up.
We just have to ignore it as it's not happening at this instant. The gremlin must be on a snack break.
Drat. Thought we had that fixed Saturday night. If it's any consolation, everyone else sees the corrected post - the excessive caching is just for the poster.