I used my laptop to upload photos onto the frame's internal memory, but the photos were so large I ran out of space. So I tried to delete the photos from the internal memory, and it will not delete. I have tried using the delete all function in the frame's menu, deleting one at a time, and plugging it into my laptop through the USB to delete. Each time, it says it's deleting, but when I turn the frame back on, the photos are still there.