Since the integration of Pocket directly into Firefox, I've noticed that when I save an article, the Pocket popup dialog has been blank. I use the extension NoScript for security purposes, and I figured that was causing the trouble, as that is not an unusual of being a NoScript user.
Today, I dug into this a little more, and figured it out. The solution is to whitelist "about:pocket-saved" in the NoScript options.
I hope this helps someone else!