Directx Tiles Shaded/Squares Error

Ok, I am developing this game engine in Vb.Net... it used the Microsoft.Directx.Direct3d namespace. I have tested this in my Win7 Laptop (the Pc I used to dev it in) my windows xp laptop but as I sent it to a friend the graphics look like this.

http://img109.imageshack.us/img109/4931/bugkt.jpg

Any reasons this maybe occuring? More info is available if you all have any questions!

It certainly looks like a texture alpha issue. I assume you have a setup file that's including any managed DirectX libraries you're using? Machine to machine I don't know why they'd be different though.

Another posibility perhaps is the (default) texture/backbuffer format being different per machine.