[Edi]

It's a setting change because of the autologout problem. Threads will stay greenlighted until you read them or use the "Mark This Forum Read" forum tool on a given forum. Note that using it on a forum with subforums will also mark the subforums read. It does not seem to work in the press releases forum because that has so many subforums. Some forums may show as having new posts even if you have read everything new in there and in its subforums (the moderator forum, for example, shows this behavior).

If you use the "Mark forums read" on the main index, it will mark everything as being read. Just learn to use and love those forum tools. Makes life so much easier.