If you are one of the owners of the Apple TV device that has been having screen flickering issues with the device after updating to the 4.2 version of the software a fix is coming. An Apple rep has confirmed that a software fix is in the works that will repair that flicker issues that some users are having.
An exact time line for the fix to land hasn’t been offered by Apple. Most of the users that are having issues with screen flicker are said to be using older HDTVs. The flicker issue is reportedly affecting sets from Sony, Panasonic, Hitachi, Samsung, and Toshiba so it's not limited to any one brand.
The flicker issue is noted to occur when the user connects directly using HDMI and with the HDMI to DVI video adapter as well. The flicker issue wasn't an issue before the new software version was applied by the users. The main addition in the software update was streaming for MLB and NBA games among other things.