ValuesGenerator implementations for a Service Plugin point can not be loaded from the plugin's classloader

Version 2.0 JIRA service plugins cannot access field *Generator's unless the class referenced by the loaded object descriptor has been 'exploded' under <jira-home>/WEB-INF/classes/com/...

For example, the snippet below shows 2 different Generator's being referenced. The first results in a java.lang.ClassNotFoundException during server startup, the second one works fine. The first one references a custom class located only in the v2.0 plugin jar, the second one is a standard Atlassian class:

<property>
    <key>project</key>
    <name>Attempt1</name>
    <type>select</type>
    <values class="com.company.jira.services.email.utilities.ProjectValuesGenerator" />
</property>


<property>
    <key>popserver</key>
    <name>admin.service.common.handler.popserver</name>
    <type>select</type>
    <values class="com.atlassian.jira.service.services.mail.MailServersValuesGenerator"/>
</property>

Once the class com.company.jira.services.email.utilities.ProjectValuesGenerator was copied under <jira home>/WEB-INF/classes/com/company/jira/services/email/utilities/ProjectValuesGenerator the ClassNotFoundException went away.

also, as an aside, the generator com.atlassian.jira.portal.ProjectValuesGenerator doesn't work, that's why I created my own and got the bug. Has to do with the BUG comment about user being cached somewhere.