iTunes won't sync some music videos to iPhone?

Hey gang-

I have lots of iTunes purchased music videos in iTunes that I also sync and enjoy on my iPhone 3gs. But I also have some music videos that I made myself from video I shot. They display and play fine in iTunes on my Mac.

But the weird thing is the ones I made will NOT sync to my iPhone. Now- I recall learning something about this a few years ago. I seem to recall iPod and iPhone are much more "fussy" than Desktop iTunes about what they consider to be a Music Video. Something to do with Metatags, but it was very specific about which ones?

Here's what I do know:

1) Both my types of music videos appear in the Music Videos Smart playlist in iTunes on my Mac.

2) When I Get Info, both types of Music Videos show Media Kind of "Music Video" on the Options tab.

3) Both play Audio and Video perfectly in iTunes on my Desktop Mac

4) But the ones I made will NOT sync to my iPhone, even though the playlist they are in is selected and "Include Music Videos" is selected in the iTunes Sync Music tab.

Can anyone remember what the "magic" is to getting iPhone to get on the same page with iTunes on Music Videos? Running iTunes 10.2.1 and Snow Leopard 10.6.6 and iOS 4.2.1 on iPhone 3gs

Thanks gang!

Dave