display port to hdmi artifacts

Hi, I have been reading lots of the forums where people are having issues with "Artifacts" being present on their screen when you go from display port to TV via HDMI. I have been having similar issues with this. The cable worked fine for several weeks, then suddenly blue, pink and green stripes appear or white noise appears. In many instances the mirror display would turn itself off and I would have to go back into the display icon and select "detect" displays - this usually did the trick and would reset itself. Recently, this stopped fixing the problem. I cam across a web forum much like this one, except in this forum the discussion was about "overscanning" which I understood it to be a problem with the Monitor or TV. The suggestion was the if your display on your Mac is set to 1080 that the output is at 1080 but that the TV or Monintor isn't capable of handling 1080 even if it is HD. The suggestion was that the HDTV isn't true HD but closer to 720. I went back into the detect display and set it to 720, and now it works like perfect again. So, maybe this will help a lot of you guys out there who are using HDTV or monitors, try setting it to 720 or ensure that your TV or monitor is infact 1080 or TrueHD. I am in no way a computer tech, so forgive my lack of correct technical terminology.