My experience is that some TV's do not interpret the HDMI signal correctly resulting in weird artifacting like faintly colored lines in the image. Texts can be hard to read. No amount of adjusting to the underscan, overscan and other options available removed this problem completely with my TV.
I think that some monitors, though they say "HD Ready".. are just not up to the job.
EDIT: I read on some articles that the Audio can mess up the definition of HDMI. Using DVI to HDMI will cut out the audio but show a better qaulity of image.
Again , this was searched threw google. Good luck Tai.