TH42pz77u Panasonic plasma, has anyone noticed that by using component inputs instead of HDMI that you get less overscan on non 1080 sources like 480p from the cable box, that seems strange since I though the overscan on different inputs was supposed to be identical but it definately is not, has anyone else noticed this?

The displayed overscan of signals depends upon the unit generated the amount of overscan. With HDMI, the TV likely generates the overscan, and with component, the cable box generates the overscan. The two devices obviously generate a different amount of overscan for the same signal.

There may be a control option in the TV that affects the amount of overscan you see in HDMI.