Hibernate serialisation failing

[klogger]

I have multiple sessionFactories, and I am using the spring-flex-core-1.5.0.M2.jar release, but when I try to return an object to the Flex client, I get the following error:

trackitude => [log level: DEBUG] [thread: http-8080-1] [logging time (ms): 154176]
   org.springframework.flex.core.io.SpringPropertyProxy.getValue [line: 85] 
      Actual type of value for property 'dayEntryId' on instance uk.co.prodia.prosoc.domainmodel.HtDayEntry@40b35cf0 is class java.lang.Integer

trackitude => [log level: DEBUG] [thread: http-8080-1] [logging time (ms): 154176]
   org.springframework.flex.core.io.SpringPropertyProxy.getValue [line: 85] 
      Actual type of value for property 'flexDayEntryId' on instance uk.co.prodia.prosoc.domainmodel.HtDayEntry@40b35cf0 is class java.lang.String

trackitude => [log level: DEBUG] [thread: http-8080-1] [logging time (ms): 154176]
   org.springframework.flex.core.io.SpringPropertyProxy.getValue [line: 85] 
      Actual type of value for property 'flexDayLineId' on instance uk.co.prodia.prosoc.domainmodel.HtDayEntry@40b35cf0 is class java.lang.String

trackitude => [log level: DEBUG] [thread: http-8080-1] [logging time (ms): 154176]
   org.springframework.flex.core.io.SpringPropertyProxy.getValue [line: 85] 
      Actual type of value for property 'htDay' on instance uk.co.prodia.prosoc.domainmodel.HtDayEntry@40b35cf0 is class uk.co.prodia.prosoc.domainmodel.HtDay

trackitude => [log level: DEBUG] [thread: http-8080-1] [logging time (ms): 154177]
   org.springframework.flex.core.io.SpringPropertyProxy.getValue [line: 85] 
      Actual type of value for property 'htDayEntryNotes' on instance uk.co.prodia.prosoc.domainmodel.HtDayEntry@40b35cf0 is class org.hibernate.collection.PersistentSet

[BlazeDS]02/11/2011 13:14:36.114 [ERROR] Exception occurred during serialization: org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: uk.co.prodia.prosoc.domainmodel.HtDayEntry.htDayEntryNotes, no session or session was closed
        at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:380)
        at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationExceptionIfNotConnected(AbstractPersistentCollection.java:372)
        at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:365)
        at org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:108)
        at org.hibernate.collection.PersistentSet.toArray(PersistentSet.java:194)
        at java.util.ArrayList.<init>(ArrayList.java:131)
        at flex.messaging.io.ArrayCollection.<init>(ArrayCollection.java:44)
        at flex.messaging.io.amf.Amf3Output.writeArrayCollection(Amf3Output.java:469)

It seems to be failing when trying to access the Hibernate proxy. I think Spring/Flex should be setting this value to a null here, but for some reason it isn't.

Here is my Spring config, I have tried it with and without the ConversionService being defined:

<flex:message-broker>
        <flex:config-processor ref="hibernateConfigProcessor" />
</flex:message-broker>

<bean id="hibernateConfigProcessor" class="org.springframework.flex.core.io.HibernateConfigProcessor">
       <property name="sessionFactory" ref="sessionFactoryProsoc"/>
       <!--<property name="conversionService" ref="conversionService" />-->
</bean>

<bean id="conversionService" class="org.springframework.core.convert.support.GenericConversionService"/>

Hints appreciated.