What are the requirements for uploading a user avatar? The Edit Profile page says "Your image must be smaller than 160x160 pixels; .gif, .jpg, .png accepted", but does not mention a file size. I have a .png which is 159x159 pixels, and is 39,158 bytes in size. But when trying to upload it, I simply receive a page that says "Pictures can be no larger than 512 bytes."

Not sure I can effectively answer your question. Pixels refers to dimensions. Bytes refers to overall size including resolution. If you are creating your own avatar, the resolution should be suitable for screen viewing and that is 72 dpi. So, an avatar that is 159x159 and 72 dpi should be much smaller than 39k bytes. Reduce your resolution first and then try uploading it.

Try it again, Pilgrim made a change that should allow you to use your image.

Aha... works fine now! Thanks for the help.