I just installed Settlers 4th edition. It opens and runs fine except for a giant black box right next to the HUD area. Has anyone else had this problem? If so what solutions did you find?

Greetings!

Even though I have never encountered this specific problem in my 10+ years playing this game, I've seen this problem a couple of times(unfortunately, as it didn't affect me, I hadn't looked further into it until now);

I have found a german topic from 4 years ago that stated that nvidia had released a new graphics driver that corrected the problem;

http://forums-de.ubi.com/showthread.php/41486-Schwarzer-balken-bei-Siedler-4-von-Nvidia-Gefixt!!-Forums

Even though I highly doubt that you are working with 4+ year old drivers, I would recommend firstly updating them(just in case).
Also, are you using AMD or nvidia as GPU? I have found out that nvidia, at least the newer cards, tend to be somewhat more unstable than AMD with this game.

Here's the download link to tha drivers, JIC;
http://www.nvidia.de/object/win7_winvista_64bit_196.21_whql_de.html

And I will look further into the problem. But please do tell us what brand of GPU(or even the exact model) are you using.

Cheers!