Still no icons with using Dev version 5.2 :( Rated 4 out of 5 stars
Still no icons in FF 14.01 displayed when selecting Options>Tool bar>Display as buttons. Strangley they will show if in Firefox select Customize Toolbar and select Use Small Icons box. Problem with doing that is all icons across the UI of FF 14.01 are just to small. Also, it seems that FF 14.01 icons are smaller than in previous versions. Hope this helps to getting a fix soon.
Oh awesome, I broke it again trying to fix a slightly different problem. Fix coming soon, or beta1 should work :D