Maybe the images are too small/big? I've noticed that even though FA re-sizes stuff (or is supposed to) sometimes the image gets lots in cyberspace because of that.
I dunno, I myself have never had this issue unless I am having connection issues. :c

did you follow the uploading instruction? therre is a certain size then certain Pix-by-Pix, then limit; how big the file is.
if thats not the problem, it might be a server issue.

You can resubmit the file by edit the submission, and then use the "change submission file".

Two years ago, I know that any file entitled with accents weren't allowed and didn't shown.

try saving in another format. if you are used to save as .bmp, try saving it as .png or good quality .jpg/.jpeg and then try uploading

i'm using all my images as .png and i'm having nice results.
bmp-like quality, .jpeg sized X3 hehe

Don't know what's up with it, but yah, I'd try editing the file after submitting and see if that fixes it. I don't know the details on size etc... but FA should resize automatically, unless its broken. Re-upping the file as an edit bypasses a lot of the stuff, like resizing, that FA tries to do with the image.