check if is driver reporting GL_ATI_meminfo extension.
GL_ATI_meminfo extension is not supported on my AMD Graphics card HD 7750. the new Drivers do not support them. The same graphics card when installed in Windows XP with relevent drivers WORKS FINE.
Does AMD have any of their own APIs for getting graphics memory information(utimization) during application execution?
I have added some more information in my earlier message.