Priority automatically set on Incidents

On the Incident entry form when the Impact and Urgency are set to "3 - Low" the Priority is defaulting after the Incident is created to "5 - Planning" and we would like it to default to "4 - Low".

I looked through the Business Rules and found one called "calculatePriority" that seems to control this behavior but even after I modify the script to

if (impact == 3 && urgency == 3)
    pVal = "4";

And activate the Business Rule it still defaults all new incidents to 5 - Planning.