Silk, just checking what you're trying to achieve...

There are two pics associated with your account. One is the avatar, which is what you see in forum comments (e.g. mine is the pink Mackintosh rose). You can also have a profile pic. This can only be seen when someone visits your profile. It doesn't show in forum posts. Check out Diamond's profile. He's got Joe Pesci for his avatar and a rather terrifying profile pic of what he looks like in real life!

Is it an avatar or profile pic you want? I just looked in settings, and it seems that your avatar should be 80x80px, though profile pics can be larger, as you've noted.