Tomcat7-maven-plugin 2.0-beta1 and useSeparateTomcatClassloader fails with run goal

I'm trying to start a web application with 'mvn tomcat7:run'. It seems
that with the configuration below it fails with the following error:

[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.tomcat.maven:tomcat7-maven-plugin:2.0-beta-1:run (default-cli) on project mantis-test-web-app: No such archiver: 'jar'. -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.

I have also tried

• 'mvn tomcat:run-war', which seems to get past this point, but then the application will not start because the 'additionalClasspathDir' property is not supported by the 'run-war' goal.
• removing 'useSeparateTomcatClassLoader' which then doesn't load the Spring instrumenting class loader required to use AspectJ LTW, specified in context.xml. I have confirmed that I get the same 'no such archiver' error if I remove the context.xml, so I don't believe this to be the cause.

Plugin configuration:

<plugin>
<groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<version>2.0-beta-1</version>
<configuration>
<systemProperties>
<log4j.defaultInitOverride>true</log4j.defaultInitOverride>
<HOSTNAME>localhost</HOSTNAME>
<port.http>9090</port.http>
<port.https>8443</port.https>
</systemProperties>
<port>9090</port>
<httpsPort>8443</httpsPort>
<path>/</path>
<useTestClasspath>false</useTestClasspath>
<additionalClasspathDirs>
<additionalClasspathDir>${project.basedir}/config</additionalClasspathDir>
</additionalClasspathDirs>
<useSeparateTomcatClassLoader>true</useSeparateTomcatClassLoader>
</configuration>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-instrument-tomcat</artifactId>
<version>${spring.version}</version>
</dependency>
</dependencies>
</plugin>