I'm running win7 connected to a 1080x1920 Logik TV. I've just changed my D-sub 15 pin connector to a HDMI one. I had no issues before trying the HDMI, the quality was quite good with the D-sub connector, but now the picture quality is not as good as it was. The audio works fine.
My video card is an ATi Radeon HD6450 1GB
I have tried:
Changing saturation, sharpness, contrast, brightness settings on the TV and PC
Changing the TV and PC aspect ratio and zoom
Changing the refresh rate
Updating the video card driver
Restarting the computer