since version 1.0.4 I get the following errror during the build of war files

...
INFO] [war:war]
[INFO] Exploding webapp...
[INFO] Copy webapp webResources to
/opt/reactor/continousintegration/hudson/jobs/PE2/workspace/trunk/cp-reactor/enterprise-manager/cp-em-war/target/cp-em-war-1.0-SNAPSHOT
[INFO] Assembling webapp cp-em-war in
/opt/reactor/continousintegration/hudson/jobs/PE2/workspace/trunk/cp-reactor/enterprise-manager/cp-em-war/target/cp-em-war-1.0-SNAPSHOT
[INFO] Generating war
/opt/reactor/continousintegration/hudson/jobs/PE2/workspace/trunk/cp-reactor/enterprise-manager/cp-em-war/target/cp-em-war-1.0-SNAPSHOT.war
[HUDSON] Archiving
/opt/reactor/continousintegration/hudson/jobs/PE2/workspace/trunk/cp-reactor/enterprise-manager/cp-em-war/pom.xml
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Error assembling WAR
Embedded error: The attribute "Hudson-Build-Number" may not occur more than once
in the same section
...

The configuration for my war plugin looks like:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<configuration>
<!-warSourceExcludes>WEB-INF/lib/*.jar</warSourceExcludes->
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>lib/</classpathPrefix>
</manifest>
</archive>
</configuration>
</plugin>

I guess that Hudson tries to set an attribute in the MANIFEST.MF resulting in
the above error state.