From the forum:
I had problems with using PayloadValidatingInterceptor with WebSphere 126.96.36.199. Only first request validation was successful while all other subsequent ones were causing errors in SaxParser.
I managed to solve problem with combination of replacing and extending XmlValidatorFactory, Jaxp10ValidatorFactory, Jaxp10Validator and PayloadValidatingInterceptor but it is not a very clean solution because field validator in class PayloadValidatingInterceptor is private field with no setter.
Problems were happening in handleRequest method in AbstractValidatingInterceptor class in line:
SAXParseException errors = validator.validate(requestSource);
SaxParser was trying to read same InputStream each time and after first time reading it (reading of xml schema) it was not able to read it any more.
Classes I had to change are in zipped attachment.
I had similar problems with CastorMarshaller class but I just replaced it with current one from svn repository (with small changes) and it was easily solved.