Yep, I'm having the exact same problem; everything worked fine until a few days ago, and even some of my composed messages--not the ones in a reply to a message--likewise do not format properly (vis-a-vis the way I have my "settings" set to format all outgoing mail). Beyond that problem, when I try to use the new "report a bug" feature, that doesn't seem to work, either; no report is ever sent, which is makes it pretty much useless!!