I don't know where to report a little bug, but there's an annoying behavior when waiting for the persona to load as preview.
You go to Personas Plus' Add-ons bar icon, then click on "Featured", choose any and wait it to load as a preview. The footer image will load in a blink on an eye. However the header image won't load. You have to select any other persona and back to the first selected persona to have both header & footer loaded.
I'm using Personas Plus on Mozilla Firefox 23 over Windows XP Professional SP3 — This issue's at least 1 year old though.
Thanks in advance.