I got a response from Vizio Tech Support:
There really is not any common cause for this issue. You mentioned that you do not have another signal source. As of this point, it could be something with the TV or the set top box. (cable box) if you had a DVD player hooked to the TV, this would tell you if there is anything wrong with the TV. If the DVD looks good but your cable box does not, you may have something wrong with the cable box.
Thank you and have a great day,
I have since hooked up a DVD via component hookup (cable box is on HDMI) and the same issue persists. Its definitely the Vizio and I am Pursuing the issue with Tech support