Updating a picture

Hello, oh wise gurus that have constructed a most tremendous training log!!!

This is so petty of me, but...
I'm attempting to update my forum picture this morning. When I click into the "Control Panel" area and go to the bottom, I see my existing avatar. When I attempt to upload a new avatar, the site appears to keep reverting to my existing avatar.

I've tried deleting my existing picture altogether, saving, then coming back and uploading my new picture. Even when I do that, my existing picture magically reappears.

What am I doing wrong?

Thank you, most wise ones. (Can I suck up or what?)