I don't know if this is this mod or if it is hardcoded or whatever, but sometimes, a faction declares war at me for no reason at all, and I can't really figure out HOW they declared war at me either...

Take one example: I play Byzantium in the Early Era. I am allied with HRE, and I even have two marriages with them. Out of no where I get the "Betrayed" message. I know, I shouldn't sound surprised. It is not like the AI is smart or anything, but what I am really wondering is how they declared war on me. They haven't attacked any of my armies or cities, they haven't blockaded any of my ports, and I am not getting any message about any assassination. They do have a crusader army on my territory, is this what is triggering a war? Or do anyone know of any other reason?