You can also set the overall forum preference to 'show all' in the acp somewhere. Even so, if you have a link you should have direct access to the topic no matter the age cutoff, unless your permissions are null. So I doubt that's the answer. I was hoping that I just couldn't see the forum.
Here's a couple links, I got a message about the links being out of date or broken, so.... :/
http://s15.invisionfree.com/Cyber_Nations/...showtopic=13483
http://s15.invisionfree.com/Cyber_Nations/...showtopic=15845
Those were the first two I could find. I've noticed most of the later links, 4-50000ish, work fine.