I ran into this same problem a few days ago. I finally got a message stating my memory was full. I’m not sure if there is a way to change the memory allotment, but I think I remember reading something in one of the forums.
All I did was re-size all of my photos. Unfortunately, I had to delete my image file in the NextGen gallery, resize and re-upload all of the images. Lucky for me I’m new to all of this and didn’t have very many photos.
Good luck to you. I hope this helps.
