Using the 855c6a4 release, I've noticed a strange behavior with a majority of users where:
"User A" (User.A@mydomain) sends a message to "User B" (User.B@mydomain). "User B" window pops up on A's screen and "User A" window pops up on B's display with the sent message. When B replies to the message, a new window is created titled "User.B@myd..." on A's display that is not selectable/expandable. A can still send messages to B, but A cannot receive messages from B.
I'm starting to poke around in the codebase a bit, but I'm somewhat unfamiliar with the project. Please let me know if this is a potential mis-configuration.