Hey OfficeSupplies,
PM2008 requires a graphics card that is compatible with DirectX 9.0 or higher. This is listed as a minimum requirement on the back of the box. The reason for this requirement is because we use something called Pixel Shader 2.0 in the game.
According to the ATI graphics card comparison listed here (http://en.wikipedia.org/wiki/Pixel_shader#Hardware), your card is just slightly too old for this. You'll notice your card (Radeon 9250) is listed as supporting pixel shader 1.4 and DirectX 8.1. As I said, this is below the minimum requirements for the game.
If you're willing to get a newer graphics card, you'll want to get a Radeon 9500 or higher.
I hope I've been helpful,
~C