I have read elsewhere you have to change a setting in IE10 to act like IE9 for this forum and other Jive platform based forums. Then you can get the reply button to work. Have you tried another browser (Chrome, Firefox, etc) as a workaround?
Sorry it took sooo long to reply here. My laptop has the new Windows 8 and I couln't reply to messages. I'm using Google Chrome here today on another computer. I have not found the IE 10 compatibility setting to mimmick IE9.