I'm trying to develop an application with Adobe Flex 2.0.1 and Hibernate. I'm using the last version of hibernate.

I have an hibernate mapping defined with some properties and a relationship:

<set name="items" table="..." lazy="false">
<key column="..."/>
<one-to-many class="..."/>
</set>

in the java bean associated with this map:

private Collection items;

On the Flex side, I'm receiving this relationship as an ArrayCollection. The serialization from java.util.Collection to Flex ArrayCollection works fine but, when I try to save the changes made on the client side ( what, on the server side, gets translated into getHibernateTemplate().update ( .. ) ), it just fails throwing this error:

java.lang.ClassCastException : flex.messaging.io.ArrayCollection cannot be cast to java.util.Set

Does anybody knows what is happening??