Inheritance of events does not work as one would expect when using working memory entry-points

When using working memory entry-points, I have a different behaviour than when I use the session.
Here is a test illustrating this:
package org.drools.test;

import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseConfiguration;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.conf.EventProcessingOption;
import org.drools.io.ResourceFactory;
import org.drools.logger.KnowledgeRuntimeLoggerFactory;
import org.drools.runtime.StatefulKnowledgeSession;
import org.drools.runtime.rule.WorkingMemoryEntryPoint;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import java.io.StringReader;

public class DroolsFusionInheritanceBugsTest {
private StatefulKnowledgeSession session;
private WorkingMemoryEntryPoint stream;
private final static String drl = "package org.drools.test;\n" +
"declare A\n" +
" @role(event)\n" +
"end\n" +
"\n" +
"rule \"myrule\"\n" +
"when\n" +
" $a : A() from entry-point \"mystream\"\n" +
"then\n" +
" System.out.println(\"fired!\");\n" +
"end\n";

@Test
public void testOkWithEventsInheritance()

{ session.insert(new A()); session.insert(new B()); session.fireAllRules(); }

@Test
public void testFailsWithEventsInheritanceThroughWorkingMemoryEntryPoint()

{ stream.insert(new A()); stream.insert(new B()); session.fireAllRules(); }

@Before
public void setupDrools()

{ KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(); System.out.println("DRL is:\n" + drl); kbuilder.add(ResourceFactory.newReaderResource(new StringReader(drl)), ResourceType.DRL); KnowledgeBaseConfiguration conf = KnowledgeBaseFactory.newKnowledgeBaseConfiguration(); conf.setOption(EventProcessingOption.STREAM); KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase(conf); kbase.addKnowledgePackages(kbuilder.getKnowledgePackages()); session = kbase.newStatefulKnowledgeSession(); assert session != null; KnowledgeRuntimeLoggerFactory.newConsoleLogger(session); stream = session.getWorkingMemoryEntryPoint("mystream"); assert stream != null : "Could not find working memory entry-point 'mystream'"; }

@After
public void releaseDroolsSession()

{ if (session != null) session.dispose(); }

}

class A {}

class B extends A { }

When using working memory entry-points, the insert of a B instances fails with a:
java.lang.ClassCastException: org.drools.common.DefaultFactHandle cannot be cast to org.drools.common.EventFactHandle