Are you using the GPU/HDMI on the motherboard itself or via a stand-alone video card (a.k.a. GPU)? If a stand-alone video card/GPU, what make and model are you using?
Last, are you using the latest drivers from either ati.com or nvidia.com, including having the HDMI drivers installed?
iam using the on board NVIDIA GeForce 8200.
my motherboard is a XFX nForce 750a SLI - motherboard - ATX - nForce 750a SLI.