devilhood: I suggest editing the dosboxDK.conf with notepad and changing fullresolution=original to fullresolution=640x480
This should hopefully fix the big black bar problem. Let me know if this works for you.
mrtnptrs: No, this does not fix this issue. I'm using Windows 8.1 by the way. It now just looks like the image above.
I had a closer inspection of the screenshot posted by RevolutionSphere, but it doesn't appear that any graphics are missing.
The black border is there because the game resolution is 640x400, and DOSBox is probably trying to display it in 640x480. This means you have 80 pixels at the bottom of the screen which are black.
There is nothing else I can recommend aside from updating your DOSBox to the
newest version.
You can very clearly see that the HUD on the left side of the screen is displaying fully.
This is a non-issue, really. Use KeeperFX if you want proper high resolution support.