How do I prevent image scaling when burning an iPhoto Slideshow in iDVD? In iPhoto '11, I have created a slideshow and sent it to iDVD 7.1.2 (Share &gt; iDVD...).

iDVD does fine with maintaining the timing, the music, the transitions, etc. However, even though I have the project set to 16:9 and under iDVD's options I have disabled "Always scale slides to TV Safe Area" the images of the slideshow are stretched vertically, compressed horizontally. No toggling of any of these options has had any effect. Burning to DVD, "burning" to image, and preview all show the same thing: stretched/compressed images.

This is not a problem of my player's aspect ratio, or my TV's aspect ratio.

How do I prevent image scaling when burning an iPhoto Slideshow in iDVD?
The only way I've found to do it is to have iPhoto render the video, and then import the video file to iDVD rather than the slideshow directly through this "integration" of their apps and letting iDVD attempt to render it. 

This worked fine, and actually didn't take as long to re-render from .mp4 to MPEG2 as I expected it would. I experienced no- or negligible loss of quality to the video during transcoding, although I'm sure that there was some as I was going from lossy to lossy format.