360 media sharing with PC

[Paladin]

I have the connections and sharing working good. I can play my mp3s, see 'my pictures' and all sub folders, and can see all of the thumbnails. However, certain jpegs have a big 'X' over them and I can't view the picture. Going over to the PC it's always portrait (vertical) pictures that have the problem. Normal landscape pictures are fine.

Does anyone else have this issue?
Any way to fix?

Thanks.