Look familiar guys.
In my case it's definitely still happening.
Happens in Win7 (Win7 is a fresh installation) and WinXP, with IE8, Firefox, or Pale Moon.
Clearing browser history and cookies does not solve it.
Happens with any type new text input, Quoted Reply, Add a Reply, Quick Reply, or Full Edit, does not happen with Quick Edit.
Best livable work around hit the Browser Back Arrow, if you refresh while the white screen is showing, it will post your message each time you refresh, very irritating!
Sometimes the back arrow does not solve it and I have to completely close and reopen the browser, that's extremely inconvenient when your time is limited you can invest here.
For me this has been happening about 3 weeks now. Ryan