title: Nexus won't download artifacts from Central
body: <p>I've just installed Nexus 2.2-01 behind a corporate proxy.  Maven is working when I go direct to the Central repo, but when I configure the <code>&lt;mirror&gt;</code> in <code>%M2_HOME%\conf\settings.xml</code>  I can't do a simple <code>mvn archetype:create</code> or <code>mvn clean</code>.</p>
  
  <p>From the Nexus web UI I can:</p>
  
  <ul>
  <li>"Browse Remote" in Central.  </li>
  <li>"Browse Index" </li>
  <li>and from the "Artifact Information" tab where it says "(Not Locally Cached)" I can download the jars </li>
  <li>and then see the .jar and .jar.sha1 files at "http://127.0.0.1:8081/nexus/content/groups/public/" and "\nexus\sonatype-work\nexus\storage\central" </li>
  </ul>
  
  <p>...but for some reason it does not download the <code>.pom</code> files</p>
  
  <p>Nexus 2.2 came with a proxy repository for Central pre-configured, and I can browse the index and download files manually from the web UI - so why won't it work from Maven?</p>
  
  <p>I have configured Nexus with Default HTTP Proxy Settings with Authentication, but still get errors such as:</p>
  
  <pre><code>[ERROR] Plugin org.apache.maven.plugins:maven-clean-plugin:2.4.1 
    or one of its dependencies could not be resolved: 
    Failed to read artifact descriptor for org.apache.maven.plugins:maven-clean-plugin:jar:2.4.1: 
    Could not transfer artifact org.apache.maven.plugins:maven-clean-plugin:pom:2.4.1 from/to nexus 
    (http://myserver:8081/nexus/content/groups/public): 
    Failed to transfer file: 
    http://myserver:8081/nexus/content/groups/public/
    org/apache/maven/plugins/maven-clean-plugin/2.4.1/maven-clean-plugin-2.4.1.pom. 
    Return code is: 504, ReasonPhrase:Gateway Timeout. -&gt; [Help 1]
  </code></pre>
  
  <p>and</p>
  
  <pre><code>[INFO] Scanning for projects...
  Downloading: http://myserver:8081/nexus/content/groups/public/
    org/apache/maven/plugins/maven-clean-plugin/2.4.1/maven-clean-plugin-2.4.1.pom
  [WARNING] Failed to retrieve plugin descriptor for 
    org.apache.maven.plugins:maven-clean-plugin:2.4.1: 
    Plugin org.apache.maven.plugins:maven-clean-plugin:2.4.1 
    or one of its dependencies could not be resolved: 
    Failed to read artifact descriptor for 
    org.apache.maven.plugins:maven-clean-plugin:jar:2.4.1
  Downloading: http://myserver:8081/nexus/content/groups/public/
    org/codehaus/mojo/maven-metadata.xml
  Downloading: http://myserver:8081/nexus/content/groups/public/
    org/apache/maven/plugins/maven-metadata.xml
  [WARNING] Could not transfer metadata org.apache.maven.plugins/maven-metadata.xml
    from/to nexus (http://myserver:8081/nexus/content/groups/public): 
    Failed to transfer file: http://myserver:8081/nexus/content/groups/public/org/
    apache/maven/plugins/maven-metadata.xml. 
    Return code is: 504, ReasonPhrase:Gateway Timeout.
  </code></pre>