Plugin configuration not being picked up from parent pom.xml

If I include the following snippet in my regular pom.xml, mvn idea:idea works as expected.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-idea-plugin</artifactId>
<configuration>
<jdkName>1.5.0_07</jdkName>
</configuration>
</plugin>

However if I include it in a parent/grandparent pom, the configuration property is not picked up and I get the "[INFO] jdkName is not set" message when running mvn idea:idea. Several other plugins have their configuration properties set from a parent pom, so I don't think this is a general mvn issue.