Auto polling offers a solution to older digital cable boxes that didn't provide a digital output for some analog channels, as it allows the 970 to switch over to the stereo analog input if the digital input remains inactive for a period of time. This sort of box was very common as recently as five years ago, but the HD cable boxes are generally not subject to it and the non-HD digital cable boxes that are around now are mostly scaled back versions of the HD boxes. Thus, you generally don't see cable boxes that have only semi-functional digital outputs anymore. Since the feature is subject to nuisance "analog checks" it's best to disable it unless you have a component that actually needs it.