Camera Roll Content Blank

I have just set up a new iPad 2 for my son (his own iCloud/Mac ID) and have migrated photos and videos from my MacBook Pro.

I sourced the required content having first backed up my own iPad and synched it with iTunes on my MacBook.

However, while I can see the photos etc in Albums on the new iPad, the Camera Roll is totally blank.

Probably something obvious but I cannot find any existing reference to this problem either in Discussions or in Using iPad.

(As I understand it one can only edit content of albums via Camera Roll as it is the master storage; so, am baffled as to why there appears to be nothing in it - yet I can access the photos in each album!)

Any ideas/advice would be gratefully received.