Strange paging behaviour with "Show unread posts"

[Halfje-Bruin]

When I click on "Show unread posts" and there are multiple pages I get the following behaviour:

• 
  [li]When I directly click on "page 2" and I get the threads displayed on the second page, this is expected behaviour.[/li]
  [li]If I first open some of the threads in a new window/tab and then click on "page 2" the first page is opened again. The clicked threads are not shown and the list is filled with new threads equal to the number I've opened at first.
  [/li]

This is quite annoying as you expect to see the new threads at the top (because of the next page thing) but they are located at the bottom.