I have one installation that sometimes doesn't want to play right.
From time to time, when I'm doing a post and click either Preview, Save Draft or Publish, it takes me to an "Oops, That wasn't found" page. All of the content completely disappears and only the title and permalink remain.
Most of the time when this happens, I can remove blocks of text until it works, but I'm not able to go back in and replace the removed text. If I do, it'll take me back to the "Oops" page.
Any ideas what may be going on?