Download of Plugins does not start

[Michel Erard]

Hello,

it's the first time I try to using maven 2. I've downloaded and made  
some changes in settings.xml:

<localRepository>/usr/local/maven_repository</localRepository>

<mirrors>
     <mirror>
      <id>planetmirror</id>
      <name>Australian Mirror of http://repo1.maven.org/maven2/</name>
      <url>http://public.planetmirror.com/maven2/</url>
      <mirrorOf>central</mirrorOf>
    </mirror>
        <mirror>
                <id>IBiblio</id>
                <name>IBiblio Repository</name>
                <url>http://www.ibiblio.org/maven2/</url>   
                <mirrorOf>central</mirrorOf>
        </mirror>
  </mirrors>


now I'm trying to create my first project with mvn archetype:create - 
DgroupId=com.mycompany.app -DartifactId=my-app
But if I start this command I receive the following Exception: The  
plugin 'org.apache.maven.plugins:maven-archetype-plugin' does not  
exist or no valid version could be found.
I think first it should start the download for some plugins? I'm not  
behind a proxy.

Thanks Mike