There seems to be a new timeout issue with viewing stories through the category search feature. I generally will do a category search then move through the stories, often leaving the browser open while I take a break, to come back and resume were I left off.
Recently, when I try to use the navigation buttons to go to the next page after taking a break, a dialog comes up stating "Invalid input. Please Start Over." This is rather inconvenient when I'm trying to scroll through a list of a couple hundred or even thousand stories. It would be nice if I could continue navigation after a break like I used to be able to.