@Michael Butterfield This is happening to me to. Its seems to happen in every browser I have tried. I have around 50 or sites and most of which this happens to. The only way to stop this is when the post has been created click back or delete the web parts and save the page. Next post you create seems fine. Its not a long term solution, just a work around.
I have reported this to Microsoft but have had no feedback as yet as to why this is happening.