Sun/Oracle JAXB RI bug? - jaxb

Question

EDIT #1: I used JAXB RI 2.2.6 (latest as of today 12/06/12), and I
observe the same behavior :-(
I am using JAXB for unmarshalling XML payloads.
When I pass an invalid payload for the first time via Unmarshaller, I get the following type of error:
javax.xml.bind.UnmarshalException: Unable to create an instance of foo.bar.FooBarType
- with linked exception:
[java.lang.InstantiationException]
On the next line in my code (in the catch() block), I try the same Unmarshaller instance and give a valid payload, where I get following type of error:
java.lang.ClassCastException: foo.bar.SomeAType cannot be cast to foo.bar.SomeBType
On the next line (again in the subsequent catch()), I try the same Unmarshaller instance and again give the same valid payload, which unmarshals fine!
Has anyone experienced this kind of behavior with JAXB? Am I hitting a bug here? Where to look/dig?
Here are the details of the manifest of JAXB jar that I am using:
Manifest-Version: 1.0
Ant-Version: Apache Ant 1.7.0
Created-By: 1.5.0_12-b04 (Sun Microsystems Inc.)
Specification-Title: Java Architecture for XML Binding
Specification-Version: 2.1
Specification-Vendor: Sun Microsystems, Inc.
Implementation-Title: JAXB Reference Implementation
Implementation-Version: 2.1.12
Implementation-Vendor: Sun Microsystems, Inc.
Implementation-Vendor-Id: com.sun
Extension-Name: com.sun.xml.bind
Build-Id: hudson-jaxb-ri-2.1-833
Class-Path: jaxb-api.jar activation.jar jsr173_1.0_api.jar jaxb1-impl.jar
Name: com.sun.xml.bind.v2.runtime
Implementation-Version: hudson-jaxb-ri-2.1-833
Thank you much in advance!
EDIT #2: It's not possible to paste everything, but here's the gist of what it is looking like:
final JAXBContext jaxbContext = JAXBContext.newInstance(FooRequestType.class);
final Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
JAXBElement<FooRequestType> result = null;
try {
//try unmarshalling invalid payload.
result = unmarshaller.unmarshal(invalidPayload.getDocumentElement(), FooRequestType.class);
}catch(Exception e1){
try {
//now try unmarshalling valid payload . ##NOTE: If you try unmarshalling Invalid Payload here, it will fail again.
result = unmarshaller.unmarshal(validPayload.getDocumentElement(), FooRequestType.class);
} catch(Exception e2){
//try again unmarshalling valid payload
result = unmarshaller.unmarshal(validPayload.getDocumentElement(), FooRequestType.class);
System.out.println("Result:=" + result.getValue());
System.out.println("Successfully unmarshalled. Exiting with (0)");
System.exit(0);
}
}
System.out.println("Not expecting to reach here.Exiting with (1)");
System.exit(1);
EDIT #3: Ran the same piece of code by using EclipseLink MOXy as the JAXB Impl; and it behaves correctly.
I opened a bug on Sun/Oracle JAXB RI: http://java.net/jira/browse/JAXB-931