I had loads of problems with full frame JPEGs (it is a 22M pixel camera though). My full res JPEGs are normally around 6-7MByte but they usually don't or didn't upload. I routinely scale them down to 1500 pixels on the longest edge and that usually works. That usually gets them below 1Mbyte. Thats more than big enough to show them on most monitors and devices - its easy enough to do though so it doesn't cause any pain but might be a problem for those uploading un-edited images.