I'm inclined to say that's not really possible (unless you have encountered some kind of bug that is).
Triggers are (more or less) based on 3 conditions: time, stats and flags (these are basically variables I set when a certain thing has taken place). I don't know if you have seen my walkthrough (that was stolen by a bunch evil pirates and posted here! -> new version hopefully up by tomorrow

), but in it I mention the required triggers for each event.
If you need any more specific information/help feel free to post/pm/mail me!