Browser: Chrome & Firefox
Link to a brief screencast video showing how to replicate: http://www.screencast.com/t/sfxQAf6u
Screenshot of same issue in Firefox: http://screencast.com/t/j6rEWXtyU
Creation of a draft post (and saving the draft) result in the post ID to be added to the URL bar (correctly).
From that state, restarting the browser or force reloading the tab causes the Chrome browser to display MANY copies of the same message.
"the backup of this post in your browser is different from the version below"
(I believe that error message is specified in wp-admin/includes/misc.php)
The problem is really not that the error message breaks anything but that it shows up more than a half dozen times, and pushes the page content way down the page.
Firefox does not trigger this message so the message itself may be the first error.
It does not seem to matter HOW you cause the page to be reloaded (meaning either ctrl-F5, or right click reload, or restarting the browser).
I should have reported this before as it's been present since at least beta 4 (and I think was in beta 3).