Hi there,
It is not a bug. The issue that you are describing is a videocard problem.

As a general rule, try these resources

1 - Check the website of your video card manufacturer and update the drivers

2 - Go to the video setup on your PC (may be different for different versions of Windows and video card); for most, click on an empty part of the windows Desktop, click on Settings->Advanced->Troubleshoot). Back the accelerations slider to the left, one level each time and see if the problem disappears. For Windows 7 --> Right Click on your desktop. --> Personalize --> display --> Change Display settings--> Advanced

3 - Right click on the wallpaper (look for a place without icons)--> Properties--> Settings--> Advanced--> Open GL--> Compatibility Settings--> Force 16 bits--> Apply--> OK

4 - Set your video color depth at 24 or 32 bits ("true color")

5 - Go to http://support.microsoft.com/kb/179113 , and see what version is current and check if you have this version installed in your computer

6 - Some NVidia card users reported additional problems--> in this case change the color settings from 32 bit to 16 bit

Now, if you the accelerations controls are not available, this means that you don't have a dedicated memory for video. In this case, go to the control panel of your video chip / adapter --> performance --> move the control and set down the performance. This may help

You'll find several discussions about this here--> search with the keywords "black screen" or "frozen image" or "texture going to the grass" or "texture going to the sky"

Patricia