Maven Sonar goal will not execute

We have a Flex Maven project and are trying to run the Sonar plugin with Maven. We are using Maven 2.2.1 and Eclipse Helios. In Eclipse we have a Maven run configuration set up to run the sonar:sonar goal. The POM file for the project has the following properties:

<sonar.language>flex</sonar.language>
<sonar.profile>Default Flex Profile</sonar.profile>
<sonar.dynamicAnalysis>false</sonar.dynamicAnalysis>
<sonar.jdbc.url>*Point to our JDBC*</sonar.jdbc.url>
<sonar.host.url>*Pointing to our Sonar instance host*</sonar.host.url>

When we try to run the configuration with the sonar:sonar goal we get an "Can not execute Sonar" error. The stacktrace with debug turned on is attached.