It's not what you think, just one member in my forum reporting that all of the forums and posts show as new posts. This obviously has to be his PC but I have to ask if there is an explanation for this? What advice should I extend when this happens? Tell him to mark all posts as read? Clear Cookies?

yah, it's an intermittent dealio -- very rare.. i have had it happen with both Firefox and Chrome...

i end up marking all read and moving along...

but i'd say there is a buglet somewhere

Yeah, it has to be him, he got back to me and said this happened on his home PC... this morning he logged in from his business PC and everything was normal. I advised him to just mark all as read and forget about it.