Dale, this just happened to me for the first time. Do you make all or most of your replies in the "Quick Reply" box? I think it really means it when it calls it quick. I usually use the reply button at the top of the most recent post, but today, I started my reply in the quick box, dilly dallied and shilly shallied and lost my whole post to the dreaded "This form is no longer valid. Please click the back button and try again." Well, of course by hitting the back button, my reply became sucked in by cyberspace and I had to start all over again.