I changed the ajax settings for the posts webpart to:

  • Enable Asynch Load: checked
  • Enable Async Update: checked
  • Show Manual Refresh Button: checked
  • Enable Async Auto Refresh: checked
  • Auto Refresh Interval (seconds): 60

I've seen three issues:

  1. The "Enable Async Load" option never stays checked. 
  2. Whenever the post webpart refreshes (manually or automatically) a textbox is added between the textarea to enter a new post and the post button.  Aside from looking weird, the watermark functions get confused if you start typing in either one of the controls.
  3. If you have started typing in a post to add, it gets erased after the resfresh happens (manually or automatically).  I can't tell if the who textarea is getting replaced, or if it is just removing the text inside.

I would expect the ajax refresh to leave the "new post" controls alone and only update the published posts.  I'm running IE9 on Windows 7.  I was also able to reproduce in Chrome on Windows 7 and IE10 PP1 (with browser mode set to IE9 and document standards set to IE8) on Windows 7.  I've attached a screenshot after a refresh.