I had a problem like that some years ago and apparently there is a setting that limits the size (in MB) of a map. You could either contact the admin or just downsize your map.
I scaled it down as much as I could while keeping the image quality decent. I'll have to contact the admin.
Cristina! I wonder if shouting for her on AP will work.
Ah shoot, now I really do have to see if I can help.