You can use the Mark All Read. That will make all the posts disappear, and threads posted to will appear on top of each other. But it's only a half help, because it also makes it very hard to find something in previous posts, once they're all gone. As SamTherapy said: The software is ancient.

FREEBIES! | My Gallery | My Store | My FB | Tumblr |
You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.