[midPoint] Why does script in schemaHandling execute twice?

[Maxwell, Gary]

Can someone tell me why the following script executes twice? The first execution uses the existing isActive value, the second time uses the value I changed it to.

<resource>
<schemaHandling>
<objectType>
<attribute>
<inbound>
<source>
         <name>isActive</name>
         <path>$focus/extension/isActive</path>
 </source>
<expression>
<script>.
<code>
	If (isActive == true)
		return false
</code>
</script>
</expression>
<target>
	<path>extension/isActive</path>
</target>
</inbound>
</attribute>
</objectType>
</schemaHandling>
</resource>