Thanks to JetZero, it was realized that artists could only submit 4-5 pieces of artwork. After some exploring of the admin options, I found it was set to let registered users only upload to about 1000k of art. That isn't all that much, is it? Well, I tweaked it so that it's unlimited now, so artists can upload as much as their little hearts desire.
Also, the fanart section has been really really really slow. Please don't feel shy! Fling me an email and join up on the fanart section. Only a small few of the artists from Atomic Fire have migrated over so far. I'd really like that section to grow and have a huge collection.