title: org/codehaus/plexus/archiver/jar/JarArchiver (Unsupported major.minor version 49.0) - Maven build error
body: <p>Afternoon all, </p>
  
  <p>I am receiving the above error when trying to build my project. I'm pretty sure this has something to do with Maven's latest update being compiled using Java 1.6 and the project we are trying to build is a 1.4 project. The plugin prior to this worked without problems, so I have added the following to the POM.xml file to try to force the existing plugin to be used.</p>
  
  <pre><code>    &lt;dependency&gt;
          &lt;groupId&gt;org.codehaus.plexus&lt;/groupId&gt;
          &lt;artifactId&gt;plexus-archiver&lt;/artifactId&gt;
          &lt;version&gt;1.2&lt;/version&gt;
      &lt;/dependency&gt;
  </code></pre>
  
  <p>But it continues to fail.</p>
  
  <p>Any help would be much appreciated</p>
  
  <p>Thanks</p>