Work Item>Attribute Customization: How do you get a calculated value to re-calculated every time the WI is saved?

We have a field on our Work Item's that calculates the number of links.  This is done through a Script Based Calculated Value written in javascript.

The issue we have is that despite the documentation stating otherwise https://jazz.net/wiki/bin/view/Main/AttributeCustomization#Script_based_calculated_values

the field does not recalculated each time the work item request is saved.  We know it works because we've made it dependant on an unrelated field.  When changing the value of that field, it does return the correct value.

How do we get this script to run every time the request is saved?