Events reset themselves if you don't use a switch to stop them.
I don't know XP but this is basically what you need to do to stop an event from repeating;
Start a condition branch with switch 001
If switch is off;
Event, event, event, turn switch 001 on.
If switch 001 is on;
Just put nothing. ( or what ever you want the event to do after it's been activated )
I hope this can be translated into XP