1. Since that latest patch, I've noticed that the API function SendAddonMessage() activates the CHATMSGADDON event on the sending character but fails to do this on other party members. I wrote a small addon for testing alone on 2 characters in a party and the behavior is consistently seen. Any ideas on what changes to this function have occurred?

    Solution found: RegisterAddonMessagePrefix('prefix") is needed to allow listening. Interestingly, the Addon worked up until now.

    That was a recent (documented) API change. Blizzard notified us about the change. Sorry, I would have responded accordingly if I had seen this =)