OpenGL Texture behavior in Mac and Linux

Hi,
I am generating a layered texture object by blending texture images. I am getting well-blended images when I run the same program on a Mac machine. But when I run the same program on a Linux (red hat 9 and mandrake) I do not see the textured images. You can have a look at the textured images on www.cs.umbc.edu/~poonam2

But can anyone please help me? I checked the versions on Mac and Linux for OpenGL and Mesa and they are the same :frowning:

Thanks for any help!!

Poonam