Cropped image on PS3 playback of avchd?

Hello.

I have burnt onto disc (using imgburn) an 720p avchd file to playback on my PS3. Unfortunately the the image seems cropped or even that it is framed too high with a large black bar at the bottom of the screen. (Taking almost 1/2 screen) I can see part of the image at the top but it is of the screen but it is a far cry from widescreen as the image is cropped and no black bar is even present. However when playing this file on my computer it seems fine. I have also tried another file literally

right afterwards, however it was 1080p file, but it had no problems. Would this be the issue? Or is it the way it was burnt. Also I tried the 720p file on my computer and it displays just fine. Could it be a setting on the ps3?

Any help would be greatly appreciative.

Thanks.