Thumb Images Reordering

There seems to be an issue with the thumbnail section of getsignoff. Once I have added quite a few images, they seem to reorder themselves however they want. Sometimes it will be a couple images where the order will change, but the most common issue is just one image changing order.

I have put the images in order numerous times but they keep reordering themselves. Any ideas or suggestions would be greatly appreciated.

Kindest Regards