Using IFO Edit to change Aspect Ratio to 16:9 - Odd Problem

[jmone]

Some background, I:
- record on my JVC DV2000 in Anamorphic mode
- capture / edit using ULED VideoSTudio6
- create the ISO files using DVD Movie Factory
- Use IFOedit to change the flags of the ISO files to 16:9 - Automatic Letterbox
- create the DVD Image then burn using DVD Movie Factory

On my PC it play in 16:9 Letterbox fine. On my PS2 it plays in 4:3. By examining my finished DVD I'm certain there are no 4:3 flags left in either Video_TS and VTS_01_0 files. Any hints why the 4:3 display from the PS2 (it plays commercial 16:9 properly)?
Thanks
Nathan

[jmone]

Mmmm I've now tested the disk on a standalone DVD Player and it played in 16:9 as you would expect. So the question is why would the PS/2 play in 4:3 (remember it plays commercial DVD's in 16:9)????