We've got a custom definition for strikethrough, though the current version of vBulletin seems to have it built-in. I looked to see if I could tweak...
Yes, it looks like either a browser or OS thing. I get the same thing in Chrome, though I can see tooltips for the blank spots and the strikethrough...
Well that's just weird. I don't see any icons in that position; just a couple of blank spaces which (when clicked) offer to wrap tags around text. No...