I have a 10.1 inch digital picture frame and I am using a 15 GB thumb drive. It is not displaying all of the pictures that are saved on the thumb drive. I don't know if it is only compatible with smaller thumb drives around 8 GB or less. I had this issue with another brand of digital picture frame but I don't see the size requirement listed anywhere in the user guide.
Yes all of the pictures are the same format. However, there are already pictures loaded onto the frame. So I will choose the thumb drive to play and it will start playing those pictures. Then after a while it switches over to the pictures already loaded onto the frame without warning.