Could your changes have affected the Find function. On Firefox usually putting "[n" in the find box allows me to go to each new post by simply hitting the Next arrow. Now typing in the "[n" gets me to the first new post but then hitting Next highlights the "[n" in the Find box and gets me no farther. Strange.

IME, that is a common Firefox bug that has nothing to do with what web site you're on.

The fix is to close Firefox and open it again.

Or even just close the tab you're having trouble with, and opening the site in a new tab.

P.S. Of course, if you do that, you'll nuke all your "new" flags.

What I usually do is finish reading the thread by positioning the cursor below the first "new" flag, then typing a square bracket into the search box again. That takes you to the next "new" flag. Do the same thing again - position the cursor below that new flag, and type a square bracket into the search box again. It's a pain, but it works.

Once you've read all the new posts, then open the thread in a new tab.

Shift+reload fixed the problems for me (Firefox + XP64)

BTW does anyone have a good workaround for the fact that searching for "new]" always scrolls the browser (Firefox & IE at least) so the [new] line appears right at the bottom of the screen, so you then have to scroll down further to see the message? One way around it is to search backwards through the posts as the [new] then appears at the top and the comment is readable directly. Makes following a threaded conversation tricky though. :-)