This won't stop the messages (although the AI eventually gives up trying - usually quite quickly) but if you set a trigger such as:
T: diplomacy locks ON LOOPING
C: (not necessary - optional)
E: diplomacy-----source player X to target player Y----relationship whatever
and repeat in the effects list every diplomacy you wish to lock, the computer may try to change diplomacy and send messages to that effect but every time it reads through the trigger list it will have to set it as you wish. It reads the list approx twice per second.
The total effect, is that in spite of an attempt and message or two, the computer will do what you want.------------------
quote:
"Always keep your words soft and sweet; you never know when you may have to eat them."