Preemptive authentication doesn't work

It seems preemptive authentication in Maven using httpclient wagon provider doesn't work. With configuration taken form [1] Maven knock to repository (tested with Artifactory 2.2.5) as anonymous user.

<server>
<id>repo-id</id>
<username>user</username>
<password>pass</password>
<configuration>
<wagonProvider>httpclient</wagonProvider>
<httpConfiguration>
<put>
<params>
<param>
<name>http.authentication.preemptive</name>
<value>%b,true</value>
</param>
</params>
</put>
</httpConfiguration>
</configuration>
</server>

Confirmed by independent party also with Maven 2.2.1. I can sniff http traffic if needed.

[1] - http://maven.apache.org/guides/mini/guide-http-settings.html