iMovie keeps outputting interlaced.

[G5Unit]

I have 2 videos:

http://www.vimeo.com/1140831

http://www.vimeo.com/1039501

The top one was filmed the exact same way as the bottom one.

Yet the bottom one is exported from iMovie very interlaced, and the top one is not.

I use the same settings on both yet get different results.

I have tried so far everything I know. Anyone know a quick fix?