The problem can also be reproduced with the HD3D SDK samples. However, it is necessary to turn VSYNC on.
I've found some other software that doesn't suffer from the sync isses of HD3D, quad-buffered OpenGL and quad-buffered DirectX. In addition it supports HDMI 1.4 frame packing in windowed mode (the HD3D SDK doesn't allow windowed mode), obviously using a hardware overlay. Why has AMD not mentioned in the HD3D SDK that there's an additional way to activate HDMI 1.4 frame packing? Were can I find the documentation?