Issue Resolved.

Note to all newbies:

Learn to be patient and walk yourself through the problem (ehm, if you haven't already). Don't be like me and spit venom when something goes wrong and you can't understand why. Chances are you will be deleting your post five minutes later and writing something like this.

In this case I had created a second instance of Shoutbox to be displayed in the forums. Problem with that is that I hurried through the process and probably missed a very important detail. Don't ask me what it might have been. Anyway, at some point an unexpected error occured and prevented certain pages from being displayed. Instead of taking my time to really track down the problem, I tried one solution, which only caused further problems, and immediately came here for help. Once I had finished my post, a thought had occured to me and I went back to the Admin panel. There, I uninstalled the faulty Shoutbox clone that I had made. Problem solved.

Sometimes the solution is right under your nose. If you're in a hurry you will most likely overlook it. Take your time.

Hope that helps somebody down the road. Helps me just getting it out.

Seems to be displaying fine to me...

Thanks brash. I just found the problem. Right when I thought I'd reached my limit of cleverness. Turned out to be a faulty Shoutbox instance.... I didn't do the conversion right.