Mp4 different - why



I used Recode 2 to create a small MP4 file from a DVD on file. Worked great, played great.

I then downloaded it to my P900 smart phone. Couldn’t play. I created an MP4 file on the phone. Played in Nero (and QT) great.

I looked at the difference in header. The Nero Recode digital format says ftypisom . The one created on the phone says ftyp3gp4.

I would like to be able to create, using Recode 2 an MP4 file playable on the phone - I guess there is a version 3gp of an MP4 format.

Any ideas appreciated.