on Ubuntu 11.04 and newer don't work OpenGL/OpenCL interoperabilty. at least not for me. for some reason it use libGL.so from mesa even when ldd tells that it use libGL.so from fglrx. in fact it open mesa libgl.so when you create a shared CL/GL object.
so to fix export LD_LIBRARY_PATH=/usr/lib/fglrx/