I'm getting that message about half the time when I reply to a post. Going back one page to the reply I just wrote with the "back" arrow and hitting "refresh" clears the problem and my comment posts OK.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!