Ipod, 7th gen, 160gb and iTunes 10...mpeg-4 (.mp4) files dont copy from iTunes to iPod

Ipod, 7th gen, 160gb and iTunes 10...mpeg-4 (.mp4) files dont copy from iTunes to iPod

Friend gave me 6 movies on a disk. All .mp3.

Four files made it to the iPod. Two failed.

Error message: "___ (movie name) not copied to (ipod name) "because it cannot be played on this ipod."

Can't find a decent fix. Please help!

macbook pro, OS 10.6.8

thanks!