problem with the quartz scheduler

hello everybody,
we are running a 5.1.6 nuxeo ep.
we tried to schedule an event which should be sent every second (see sourcecode below).
we've also written a listener which works properly (tested with other predefined events).
the scheduler doesn't work, it isn't executed or registered (telling from the info log).

scheduler-service-contrib.xml:
------------------------------------<?xml version="1.0"?>
<component name="de.ancud.scheduler.HelloWorld.schedulerTest">
<implementation
class="org.nuxeo.ecm.platform.scheduler.core.service.SchedulerRegistryService" />
<extension-point name="schedule">
<schedule id="helloWorld">
<username>Administrator</username>
<password>Administrator</password>
<eventId>testEvent</eventId>            
<eventCategory>default</eventCategory>
<cronExpression>*/1 * * * * ?</cronExpression>
</schedule>
<object class="org.nuxeo.ecm.platform.scheduler.core.service.ScheduleImpl" />
</extension-point>
</component>
------------------------------------
event-listener-contrib.xml:
------------------------------------<?xml version="1.0"?>
<component name="de.ancud.scheduler.HelloWorld.event-listeners">

<extension target="org.nuxeo.ecm.core.listener.CoreEventListenerService"
point="listener">