Editing messages has developed a poltergeist

I tried to edit a message by hitting up and editing the text soon after opening a room.  The send button of the edit dialog was greyed out however.  I then tried to use the cursor keys to move up & down again to fix it, but the UI went berserk, jumping back and forth between which tile was being edited, as if inhabited by a poltergeist.  It didn't stop until I changed room and back again.