When using WinDVD or PowerDVD, it will report a 16:9 DVD in a 720x480 aspect ratiom but 720:480=1.5 : 1, on the other hand, AE100's resolution
is 852x480 which is 1.85 :1= 16:9. SO I just wonder why the PowerDVD will report the NTSC DVD signal is 720x480 but not 852x480??
I think I see where you are going.... All DVDs are actually 4:3 even the widescreen ones but with black bars at the top and bottom (letterboxing). Anamorphic DVDs will actually take up the entire vertical resolution but when they are squeezed to varying degrees the result is the widescreen image.
PowerDVD is reporting the native resolution of the disc, your HTPC or scaler is the one working to make it 852/856x480.
BTW you may want to search through the HTPC forum because I still feel like I am not answering your question.