It seems to me that OpenGL extension wglSwapIntervalEXT does not work correctly.
I use X4500 (G41) on Windows XP with latest driver (2010/7/20 126.96.36.19984).
Although control panel setting (VSYNC global ON/OFF) works fine, application setting (per GL context) seems to be ignored.
Same program works as intended with nVidia GPU.
I hope this problem will be corrected shortly.
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