I have been researching how to get the best DVD picture out of my HDTV.  I have a RP HDTV (Toshiba 61hx70) and a Sony   Progressive scan DVD player ( dvp-ns425p).  My xbox is running HD and I have a box from the cable company that converts to HD signal.  Do I have to have a HD converter to view DVDs in 480p?  When I turn on or off the progressive scan it looks no different to me.  I guess maybe my TV doesn't support 480p.  Man this is confusing.  I have everything I want in HD but DVDs.  Can anyone advise me?  I promise I will pass on the info to other people.