I don't get it. I made a widescreen DVD using iDVD '06 and it plays fine in widescreen on both my Macs.
However, it is 4:3 on my standalone DVD players. The strange part is that it isn't squished. The sides are cut off, as if the DVD player is defaulting to automatic pan & scan or something. I tried it on two different DVD players with the same result.
It seems I just wasted 2 hours making this DVD, which doesn't work properly.