Photos turned to black

[DMC]

Hello all,

I'm experiencing a weird thing. I searched to see if it's been discussed already and I didn't find my specific problem anywhere.

When scrolling through my camera roll thumbnails, all of the pics are there and I see them. However when I selected a pic, it turns black. Please see the image below:

You can see the plant pic in the thumbnails but when I selected it, it turns black.
.

It's not all of the pics, maybe 8 or 9 random images.

I've never seen this happen prior to the ios7 upgrade.

Any thoughts?

Thanks!!!