I had been working with Werner Guttman lead of the Castor XML project on ideas for extending the Spring OXM for current Castor version. I've prepared a patch with change made to CastorMarshaller unmarshalling methods, so that they will use Castor API and 'native' support for StAX.
You will find two patches attached, one with changes made in implementation and second with changes made in ivy build file and manifest file.
Before resolving this task, could You please resolve the issue in EBR (https://issuetracker.springsource.com/browse/EBR-747).
So that the Spring OXM could use the current Castor version (1.3.2)