Maybe we just have different techniques of navigating through this site. My MO was to click on the "back" button and go back two pages after reading a thread. That has the effect of erasing the red "new" tag and I don't have to go to that thread again until the red tag re-appears. That was working for me until a few weeks ago and only started working again a few minutes ago. In the meantime I was resorting to using the refresh button on the task bar which is a bit more cumbersome.