Here's a screendump from ubbcentral to show what I mean.

[Linked Image from trosfrihed.dk]

It seems to be a small bug in /scripts/showflat.inc.php

Find 1/3 down the page this codesnippet in /scripts/showflat.inc.php
PHP Code
if (!$page) { $page = 1; }
		
	if ($gonew && !$nt) {
		$nt = $page;
	}
  


Edit code to:
PHP Code
if (!$page || $mode == "showthreaded") { $page = 1; }
	//if (!$page) { $page = 1; }
	
	if ($gonew && !$nt) {
		$nt = $page;
	}
  


All topics might be displayed in threaded mode (if enabled in CP)