Generally, I keep about 8 photos in the Gallery, and each is a little less than 1 megabyte in size. Every now and then, or when I edit a new photo, this is what happens: - One or more photos are blacked out. - Several photos just disappear, as though I had never even downloaded them. The N4 is a 16 GB model, and these are my stats: SD card 3.07 GB used; Emulated 6.15GB used. Hope there's a solution for this... I really like the N4 and am waiting to see what new models come out in October. Thanks!