Division by zero

I have developed an OPENGL based program which runs fine on all computers providing the graphics card is not an ATI Radeon type. It gives me a DIVISION by zero when I run this. Has anybody come across this problem before

Very likely you divide something that you get from OpenGL and what is not supported on ATI. There are differencies in card/vendor/driver capabilities, so you should debug your program on system similar to problematic (one with radeon card).