Using FF 3.0.6 and OpenGoo 1.2RC2
HTML formatted emails cause the "Actions" links in the right col. to inherit font-size.
(See image)
Top portion of screen cap is a plain text email opened to view and the lower portion is a message formatted in html opened.
Seems like the "Action" links and text shouldn't be resizing based on the content of the email since it is part of the interface.
According to firebug the action text css is initially inherited from the body tag (plain text). On the HTML Message it's inherited from the messages inline font-size on the table tag.
HTH
Travis