Background graphics on my machine are all broken.
It looks a bit strange because we have tested in many computers and all of them it worked correctly. You have to know that the game only works on windows with 64-byte architecture and in Mac and Linux using Wine. The architecture of the system could be the problem or perhaps the OpenGL version installed in your computer.
Well, you will probably have an app installed in your computer to control the graphic card on your computer. Find that program or you can try to install OpenGL Extensions Viewer. It is an app that i know. Check the opengl version in C++ could be an idea to solve these kind of problems. Concretly, I use the OpenGL 6.14.10.13440 version.