User Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.7; en; rv:22.214.171.124) Gecko/20120308 Camino/2.1.2 (like Firefox/3.6.28) Build ID: 20120308211433 Steps to reproduce: I tested many times and found that when I went back over a sentence and corrected a typo, and then tried to continue typing, the font became very tiny, no matter if I was in Original HTM, SIMPLE HTML, OR TEXT. If I typed the entire message without manually correcting anything as I went, the font held and I then corrected when I was entirely finished. Actual results: My messages will now type properly as long as I don't correct until I am all done.
This manual fix is not a true "fix" and needs to be addressed. Several others have listed this as as bug.
jberger416, Thanks! This does look like a duplicate of https://bugzilla.mozilla.org/show_bug.cgi?id=793527.