I don't know about White Box, but there is another thread about this, which I will try to find.
You may want to follow this thread and see how it went for the user and consult with him/her.
This is a common issue for ATI Radeon users. Many linux distros have problems properly identifying the card correctly.
What I do know, is that if the kernel source and header packages are not installed by default, you have to add them.
How far you want to go with this depends on how much experience that you have with Linux.
The other suggestion is to check out the White box web site to see if they have an answer for your issue.
The other thread is located at the following;
http://www.linuxcompatible.org/forums/viewtopic.php?t=1460Also, here are the install instructions, that will give you an idea what you need to do.
http://www.ati.com/support/infobase/linuxhowto-ati.htmlAnother thread that discusses the problem;
http://manhunt.thegoodtimes.ca/forums/index.php?act=ST&f=3&t=2961