undertow claims already registered

I've downloaded wildfly beta, attempted to add a vhost using the undertow configuration (can't find documentation btw) but when it starts, it says:

org.jboss.msc.service.DuplicateServiceException: Service jboss.web.common.host./ is already registered

I originally posted the question here:
https://community.jboss.org/message/842352

The relevant config section (standalone.xml) is the following:

<subsystem xmlns="urn:jboss:domain:undertow:1.0">
<buffer-caches>
<buffer-cache name="default" buffer-size="1024" buffers-per-region="1024" max-regions="10"/>
</buffer-caches>
<server name="default-server">
<http-listener name="default" socket-binding="http" max-post-size="10485760"/>
<host name="default-host" alias="localhost">
<location name="/" handler="welcome-content"/>
</host>
<host name="other-host" alias="www.mysite.com" default-web-module="something.war">
<location name="/" handler="welcome-content">
<filter-ref name="connection-limit"/>
</location>
</host>
</server>
<servlet-container name="default" default-buffer-cache="default" stack-trace-on-error="local-only">
<jsp-config/>
<persistent-sessions path="persistent-web-sessions" relative-to="jboss.server.data.dir"/>
</servlet-container>
<handlers>
<file name="welcome-content" path="${jboss.home.dir}/welcome-content" directory-listing="true"/>
</handlers>
</subsystem>