After switching from Alpha to Beta 1 I get the following message:
"Duplicate collection role mapping BusinessObjects.Person.Address"

I have not changed the code. In Alpha it worked with out any issues!

" at NHibernate.Cfg.Mappings.AddCollection(Collection collection) in c:\\net\\nhibernate-1.2.0.Beta1\\nhibernate\\src\\NHibernate\\Cfg\\Mappings.cs:line 98\r\n at NHibernate.Cfg.HbmBinder.PropertiesFromXML(XmlNode node, PersistentClass model, Mappings mappings) in c:\\net\\nhibernate-1.2.0.Beta1\\nhibernate\\src\\NHibernate\\Cfg\\HbmBinder.cs:line 1436\r\n at NHibernate.Cfg.HbmBinder.BindRootClass(XmlNode node, RootClass model, Mappings mappings) in c:\\net\\nhibernate-1.2.0.Beta1\\nhibernate\\src\\NHibernate\\Cfg\\HbmBinder.cs:line 467\r\n at NHibernate.Cfg.HbmBinder.BindRoot(XmlDocument doc, Mappings mappings) in c:\\net\\nhibernate-1.2.0.Beta1\\nhibernate\\src\\NHibernate\\Cfg\\HbmBinder.cs:line 1724\r\n at NHibernate.Cfg.Configuration.AddValidatedDocument(XmlDocument doc, String name) in c:\\net\\nhibernate-1.2.0.Beta1\\nhibernate\\src\\NHibernate\\Cfg\\Configuration.cs:line 408"

[code]
Address.hbml.xml
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
<class name="BusinessObjects.Address, BusinessObjects" table="ADDRESS" dynamic-update="true" lazy="false">
<id name="Id" column="ADDRESSID" access="nosetter.camelcase" unsaved-value="0">
<generator class="identity" />
</id>
<property name="Address1" column="Address1" not-null="true" />
<property name="Address2" column="Address2" />
<property name="City" column="CITY" />
<property name="State" column="STATE" />
<property name="ZipCode" column="ZIPCODE" />
<property name="Country" column="COUNTRY" />
<many-to-one name="Person" column="PERSONID" not-null="false" />
</class>

[code]
Person.hbml.xml
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
<class name="BusinessObjects.Person, BusinessObjects" table="PERSON" discriminator-value="?">
<id name="Id" column="PERSONID" access="nosetter.camelcase" unsaved-value="0">
<generator class="identity" />
</id>
<discriminator column="PERSONTYPE" />
<property name="Title" column="TITLE" />
<property name="FirstName" column="FIRSTNAME" />
<property name="LastName" column="LASTNAME" />
<property name="MiddleName" column="MIDDLENAME" />
<property name="PhoneNumber" column="PHONENUMBER" />
<property name="UserName" column="USERNAME" />
<property name="Password" column="PASSWORD" />
<property name="Email" column="EMAIL" />
<property name="PasswordQuestion" column="PASSWORDQUESTION" />
<property name="PasswordAnswer" column="PASSWORDANSWER" />
<property name="CreateDate" column="CREATEDATE" />
<property name="ExpirationDate" column="EXPIRATIONDATE" />
<property name="LastLogin" column="LASTLOGIN" />
<property name="LastIp" column="LASTIP" />

<!-- START ADDRESS-->
<bag name="Address" inverse="true" lazy="true" order-by="CREATEDATE" cascade="all" access="nosetter.camelcase">

<key column="PERSONID" />
<one-to-many class="BusinessObjects.Address, BusinessObjects" />
</bag>
<!-- END ADDRESS-->


<!-- START PROFILE-->
<one-to-one name="Profile" property-ref="Person" />
<!-- END PROFILE-->

<subclass name="BusinessObjects.Caster, BusinessObjects" discriminator-value="Caster" />
<subclass name="BusinessObjects.Agent, BusinessObjects" discriminator-value="Agent" />
</class>
</hibernate-mapping>
</hibernate-mapping>[/code]

I have not looked in the source code what has changed...that will follow later but -

If you add a class to the config and add an assembly that contains the class too, Beta version fails where as the Alpha was fine...

Please submit this to JIRA with a simple test case.