Amiga.org seems to have a few problems uploading images of any sort.
I have 3 browsers on a Mac and it will not accept data from any of them (Safari, Camino, IE).
I usually have to resort to the indignity of uploading with IE on Windows (which is dial up only).
I have a heap of interesting* images to upload but I'm not going to do them via dial up.
*Ever seen inside the Walker???