Hrm, I've had a similar experience except in my case deleting the second post results in the first one being deleted as well, not really a big issue because the draft feature saves what I was writing but eh.
I've noticed that in the occasion when two posts appear, one is a phantom. If I reload the page, there is actually only one post afterall.
I done awesomed.
Can i filter posts from showing up on my "all" tab by forum?
yes, go to the categories tab, hover over a "forum" and you will see a gear appear at the right, just unfollow it. Those you unfollow, will not be included in the "all" tab
...and less disturbing.