I belive that was an issue from a prior version. First off I would make sure you have the latest. If that does not resolve the issue, you can go into Carb's options and under the Privacy and Comm section you can uncheck some of the communication options. Unchecking them will prevent Carb from talking to others or spamming your Friend's status.
*I don't remember exactly which ones to turn off to stop those messages.. Worst case, uncheck a couple, see if the spam stops