As a follow up to my previous post about MarsEdit, I was having an issue when trying to upload images. I was getting a really useless error :

It is not possible to upload the file, because it exceeded the maximum filesize of 0 bytes

So check the prefs inside drupal :

Right. Something’s not quite talking there. It turns out the problem was in permissions. Although I’m logged in as user 1, which on the site has every privilege, the blog api uses the proper roles and won’t allow you to upload if the permissions for your role doesn’t have it explicitly set. When I turned on the correct privileges all was good again.