I'm sure I will find out eventually, however I'm curious if this is related to having Multiple Curing Classes (Shm & Clr for me) in group and when fighting a Named or event that puts debuffs on group, they begin to endlessly Chain Cast various cures on each other usually but can be themselves or some particular group member.
When this has happened (a lot of times) I always have to camp them both to Server Select at least and then back into game to "fix" the issue. Character Select is not out far enough.
Thank you very much ALL involved in coding/testing/(and the water bearers)
~TheFiddler~