I didn't originally think this was possible... and yes, I know many people cringe at stretching 4:3 movies, but for kids TV shows on DVD, my kids don't care and I'd rather burn in my plasma screen evenly (since Kaleidescape doesn't offer gray sidebars).
This can be done by going to the installer page, then the components tab, then the link for the player you want to change.
On step 4, for "NTSC 4:3 full screen DVD" - select "480p (4:3 full screen)". Make sure you've checked that option as a valid output type in Step 2 as well.
Voila - 4:3 shows will now stretch to full screen.
I only wish they also had "720p 4:3 full screen" so my plasma doesn't have to switch resolutions, which shows a bunch of garbage on the screen for a few seconds while it switches over.
This can be done by going to the installer page, then the components tab, then the link for the player you want to change.
On step 4, for "NTSC 4:3 full screen DVD" - select "480p (4:3 full screen)". Make sure you've checked that option as a valid output type in Step 2 as well.
Voila - 4:3 shows will now stretch to full screen.
I only wish they also had "720p 4:3 full screen" so my plasma doesn't have to switch resolutions, which shows a bunch of garbage on the screen for a few seconds while it switches over.