JAAS/Tomcat: LoginException with NTLoginModule

Question

I have setup Tomcat to use the NTLoginModule, but when logging in, I get a:

javax.security.auth.login.LoginException: java.lang.ArrayIndexOutOfBoundsException
    at com.sun.security.auth.module.NTSystem.getCurrent(Native Method)
    at com.sun.security.auth.module.NTSystem.<init>(Unknown Source)
    at com.sun.security.auth.module.NTLoginModule.login(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at javax.security.auth.login.LoginContext.invoke(Unknown Source)
    at javax.security.auth.login.LoginContext.access$000(Unknown Source)

I guess I must have done something wrong, or something must be missing in my configuration. Do you see anything wrong with the configuration below?

Web app web.xml

<security-constraint>
    <web-resource-collection>
        <web-resource-name>Authentication example</web-resource-name>
        <url-pattern>/xforms-hello/*</url-pattern>
    </web-resource-collection>
    <auth-constraint>
        <role-name>orbeon-admin</role-name>
    </auth-constraint>
</security-constraint>
<login-config>
    <auth-method>BASIC</auth-method>
</login-config>
<security-role>
    <role-name>orbeon-admin</role-name>
</security-role>

Tomcat's server.xml

<Realm className="org.apache.catalina.realm.JAASRealm" appName="Catalina"/>

Starting Tomcat

-Djava.security.auth.login.config=C:\Program Files\Apache Software Foundation\Tomcat 5.5\conf\jaas.conf

jaas.conf

Catalina {
  com.sun.security.auth.module.NTLoginModule REQUIRED;
};