JSF application crossing user session data

Question

I have a difficult JSF issue I am trying to solve. Note, I am fairly new to JSF and Java....I have a simple application where users login, select some checkboxes, click submit, add some more info on another page, save to DB and logout.

In my Production env, I am seeing instances where user session data is getting crossed or cached and pickup by a subsequent user session. For example, User A enters data, then User B enters data and upon reviewing his data, he sees stuff User A entered. Of course, I cannot recreate this in test.

I am using jsf 1.2._12, richfaces 3.3.2, and spring 2.5.6. The app server is JBoss 5.

All of my JSF managed-beans are session scoped. This particular managed bean calls a spring bean as my Business object which is session scoped, which ultimately calls a DAO that is singleton.

Here the relavant faces-config info

<managed-bean>
    <description>ContactBean</description>
    <managed-bean-name>ContactBean</managed-bean-name>
    <managed-bean-class>com.package.ContactBean</managed-bean-class>
    <managed-bean-scope>session</managed-bean-scope>

    <managed-property>
        <property-name>dataElementBO</property-name>
        <value>#{dataElementBO}</value>
    </managed-property>

    <managed-property>
        <property-name>attributeBO</property-name>
        <value>#{attributeBO}</value>
    </managed-property>

    <managed-property>
        <property-name>dataElement2BO</property-name>
        <value>#{dataElement2BO}</value>
    </managed-property>

    <managed-property>
        <property-name>submissionBO</property-name>
        <value>#{submissionBO}</value>
    </managed-property>

    <managed-property>
        <property-name>selectedList</property-name>
        <property-class>java.util.ArrayList</property-class>
        <list-entries />
    </managed-property>

    <managed-property>
        <property-name>enteredContact</property-name>
        <property-class>java.util.ArrayList</property-class>
        <list-entries />
    </managed-property>
</managed-bean>

And my app-Context for the spring bean getting called

<bean id="submissionBO" class="com.package.submissionBOImpl" scope="session">
    <property name="submissionDAO">
        <ref bean="submissionDAO" />
    </property>
</bean>

In viewing my webserver logs, this issue occurred when User A and B weren't even logged in at the same time. User A logged out and then User B logged in almost 20 minutes later.

I don't understand how the use of session scoped beans could possibly cross in other users data... is there something I don't understand about how these are scoped? I can attach some mocked up code if needed. Thanks in advance!