If you asked some time ago and still have not received an answer, the addon may likely be abandoned. :( You could also click the "Project Site" link and ask there or open a ticket, but you may also not receive a response from the author.
Are you sure you have the latest version? Latest version is an Alpha release v1.3.3-2-g2d2244c released on 29 November 2011 for WoW 4.3. Check the "Project Site" whenever you're looking for the latest version whenever possible. In this case it's at WoWAce (http://www.wowace.com/addons/chatter/). There's also a link to it in the information block at the top of the Chatter (http://www.curse.com/addons/wow/chatter) page here on Curse.com.
Please be aware that some authors don't push an update just because the game version has changed. If there has not been a change requiring the author to change something in their code so the addon does not throw errors, some authors simply won't push an update. After all, Blizzard made it possible to run out-of-date addons, so there is absolutely no need for an author to update an addon that still works fine without changing the interface number in the TOC file.