GPU programming in Mathematica

I have an ATI graphics card in my laptop running Ubuntu 10.10. I installed the OpenCL library and tried to run programs in the GPU through Mathematica.

I imported the package "OpenCLLink" and checked OpenCLQ[] and it returned True but when I run the example from the introduction in Mathematica it doesn't work. All the program is supposed to do is double a vector. For example, with doubleFun[{1,2,3},3] the output should be {2,4,6}, but in my case the output is still the same: {1,2,3}.

What might be the cause of this problem? Is i开发者_如何学Pythont a configuration issue or something else?