Need help fixing a warning: 'Failed to getClass for org.apache.maven.plugin.source.SourceJarMojo"

[Jeff Walker]

Hi,
Can somebody please tell me how to get rid of this warning when running ou 
Maven builds:

WARNING: Failed to getClass for 
org.apache.maven.plugin.source.SourceJarMojo

I tried adding the <version> element to the plugin xml,m but it made no 
difference.
I'm guessing it has to do with the source plugin I'm using:

<plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-source-plugin</artifactId>
        <version>2.2.1</version>
        <executions>
                <execution>
                        <id>attach-sources</id>
                        <goals>
                                <goal>jar</goal>
                        </goals>
                </execution>
        </executions>
</plugin>

If you need the whole pom file, let me know.
Thanks in advance,
-jeff