VOOM integrates local broadcast channels in your home DMA into your PG. For example, my mailing address indicates that I am in the Washington DC DMA (008) and all my DC locals are fully integrated into my PG...regardless if I can receive them (stations may be at low power) or not. The channels you pick up when scanning (assuming they are outside your home DMA or not correctly identified to your home DMA) will show up in your local channels, but won't show any PG data. For example, I can pick-up channels outside my home DMA (Richmond VA, Charlottesville VA, Baltimore MD), but none of these channels show PG data since they are not integrated (Mapped) into my PG.
VOOM/Motorola has been working on a SuperDMA Map, in which you can add nearby DMA channels and have them fully mapped into your PG.
I hope this makes since I'm doing 12 things at once...