Maven with HTTP Proxy

Is there anything special you need to do to get the Maven integration to connect using a configured HTTP proxy?

The following are working correctly on my system:

• Command line Maven is working fine, specifying the HTTP proxy in my settings.xml
  
• IDEA connecting through the HTTP proxy, for obtaining things like the available Plugins

However, when I attempt to synchronize the Maven repositories  I get the following exception in my idea.log file:

Caused by: java.lang.RuntimeException: org.apache.maven.wagon.authorization.AuthorizationException: Not authorized by proxy.
    at org.apache.maven.wagon.shared.http.AbstractHttpClientWagon.fillInputData(AbstractHttpClientWagon.java:600)
    at org.apache.maven.wagon.StreamWagon.getInputStream(StreamWagon.java:116)
    at org.apache.maven.wagon.StreamWagon.getIfNewer(StreamWagon.java:88)
    at org.apache.maven.wagon.StreamWagon.get(StreamWagon.java:61)
    at org.jetbrains.idea.maven.server.embedder.Maven2ServerIndexFetcher.retrieve(Maven2ServerIndexFetcher.java:93)