FULL PRODUCT VERSION :
jdk 1.6

ADDITIONAL OS VERSION INFORMATION :
Windows XP

A DESCRIPTION OF THE PROBLEM :
I have an application where a DOM document is generated on the fly and then needs to be validated against the XML-schema.
Using JDK 1.5 (jdk1.5.0_01) this works well and the DOM is correctly validated.
When changing to JDK 1.6 (jdk1.6.0) the validation complains that the first attribute on the root element is invalid (cvc-complex-type.3.2.2: Attribute 'CreationDateTime' is not allowed to appear in element 'ODM'), this although this is a required attribute according to the schema.

Here is a snippet of my code:

//create a SchemaFactory capable of understanding WXS schemas
SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
// load a WXS schema, represented by a Schema instance
Schema schema = factory.newSchema(schemaFile);
System.out.println("schema = " + schema);
// create a Validator instance, which can be used to validate an instance document
Validator validator = schema.newValidator();
System.out.println("validator = " + validator);
ErrorHandlerImpl errorhandler = new ErrorHandlerImpl();
errorhandler.setErrorWarningVector(errorWarningVector); // some other info
errorhandler.setSchemaInformation(schemaInformation); // some other info
validator.setErrorHandler(errorhandler);
validator.validate(new DOMSource(doc)); // doc is DOM document

what I observed is that with JDK 1.5 and with JDK 1.6 the Schema objects are not the same:
JDK 1.5: com.sun.org.apache.xerces.internal.jaxp.validation.xs.SchemaImpl
JDK 1.6
com.sun.org.apache.xerces.internal.jaxp.validation.XMLSchema

When using JDK 1.6, everything becomes suddenly a bit strange.
When I first write the DOM document to file, and then do the validation using that file, everything goes fine.
But when I use the DOM document directly, validation fails.

The code:

// workaround : print the DOM document to file
File tempFile = new File("temp.xml");
DOMPrinter pr = new DOMPrinter(doc, tempFile);
pr.printDomDocument();
// end of workaround
SchemaFactory factory = SchemaFactory.newInstance("http://www.w3.org/2001/XMLSchema");
try {
// load a WXS schema, represented by a Schema instance
Schema schema = factory.newSchema(schemaFile);
Validator validator = schema.newValidator();
// read the document from the file
DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
domFactory.setNamespaceAware(true);
DocumentBuilder builder = domFactory.newDocumentBuilder();
Document mydoc = builder.parse(tempFile);
// now validate using the document from file
validator.validate(new DOMSource(mydoc)); // OK: validates fine
// validate the DOM document that was the source for writing to file
valdator.validate(new DOMSource(doc)); // gives an error (invalid attribute on root element)

P.S. Yes I did set setNamespaceAware(true) when building the original DOM.
P.S. See also http://forum.java.sun.com/thread.jspa?threadID=5134606
P.S. It was reported that the example given in http://java.sun.com/j2se/1.5.0/docs/api/javax/xml/validation/package-summary.html does not work either anymore when using Java 1.6

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
see above, or try sample at http://java.sun.com/j2se/1.5.0/docs/api/javax/xml/validation/package-summary.html


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
validator does not report an error
ACTUAL -
validator reports an error

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
take code from http://java.sun.com/j2se/1.5.0/docs/api/javax/xml/validation/package-summary.html
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
See above: write DOM to file, read DOM from file and validate (see above)

Release Regression From : 5.0u10
The above release value was the last known release where this 
bug was not reproducible. Since then there has been a regression.