I was not taking the side content. To give you an example, the main link to this current thread is
https://www.ubbcentral.com/forums/ubbthreads.php/topics/208471/Poll_Your_top_feature_you_want.html

Now if you go to page two and click on the link to page one the url is https://www.ubbcentral.com/forums/ubbthreads.php/topics/208471/1.html

The whole thing is even getting worse. If you click the message icons on page 1 you will get the following links, all linking to the same page:
https://www.ubbcentral.com/forums/u...l_Your_top_feature_you_w.html#Post208472
https://www.ubbcentral.com/forums/u...l_Your_top_feature_you_w.html#Post208473
https://www.ubbcentral.com/forums/u...l_Your_top_feature_you_w.html#Post208477
https://www.ubbcentral.com/forums/u...l_Your_top_feature_you_w.html#Post208482
https://www.ubbcentral.com/forums/u...l_Your_top_feature_you_w.html#Post208505
https://www.ubbcentral.com/forums/u...l_Your_top_feature_you_w.html#Post208512
https://www.ubbcentral.com/forums/u...l_Your_top_feature_you_w.html#Post208522
https://www.ubbcentral.com/forums/u...l_Your_top_feature_you_w.html#Post208527
https://www.ubbcentral.com/forums/u...l_Your_top_feature_you_w.html#Post208528

Same for the last post columns on the forums overview/topics pages.

I fixed nearly all problems on my forums, but it was a massive code modification so I am still running 7.3b5 crazy. I may redo this, as soon the final version of 7.4 is available and will document everything this time. As far I can tell you it seems to make a huge difference.