[m2] proxy settings are ignored?!

[Krause, Steffen]

Hi all,
 
For some reason I have trouble setting up the proxy in the settings.xml. This 
is the block I entered into the settings.xml but Maven2 will still not go 
through the proxy. 
 
<proxies>
  <proxy>
    <active>true</active>
    <protocol>http</protocol>
    <username/>
    <password/>
    <host>proxy.ka1.dsh.de</host>
    <port>80</port>
    <nonProxyHosts/>
  </proxy>
</proxies>
 
It always brings following error message:
 
The plugin 'org.apache.maven.plugins:maven-archetype-plugin' does not exist or 
no valid version could be found
 
 
At home where I access the internet without a proxy it works fine but here at 
work I just can't get the proxy to work. 
Anybody has an idea??
 
Thanks,
 
Steffen.