Maven Cobertura + Maven War Plugins

I have problems with these plugins, I got the following exception:

[INFO] Error configuring: org.apache.maven.plugins:maven-war-plugin. Reason: ERROR: Cannot override read-only parameter: classesDirectory in goal: war:exploded

I also found this problem in JIRA which is not resolved.

In any case, I will really like that it works. Does anyone know another plugin for this or a workaround to make it work?

Thanks in advance.

[EDIT]

I added the Cobertura plugin to my parent pom project, for example:

<reporting>
    <plugins>
        [...]
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>cobertura-maven-plugin</artifactId>
            <version>2.5.1</version>
        </plugin>
    </plugins>
</reporting>

And when I run the "mvn site", I got an exception, as I said earlier.

About JIRA problem, I accidentally insert the wrong link, sorry. Now it is updated.

BTW: I tried the workaround described in this problem, without success.