tuscany SDO beginner

[zb cong]

hello,

my first tuscany sdo program:

	       HelperContext ctx = HelperProvider.getDefaultContext();
	        FileInputStream is = new FileInputStream("......\\test.xml");
	        XMLDocument doc = ctx.getXMLHelper().load(is);
	        DataObject root = doc.getRootObject();
	       root.getString("person/name");

i import all jar under lib dir of tuscany_sdo1.1 package, when i run it, the following exception thrown at "root.getString("person/name")":

Exception in thread "main" java.lang.ClassCastException: org.eclipse.emf.ecore.util.FeatureMapUtil$FeatureEList incompatible with org.eclipse.emf.ecore.EObject
at org.apache.tuscany.sdo.util.DataObjectUtil$Accessor.process(DataObjectUtil.java:2237)
at org.apache.tuscany.sdo.util.DataObjectUtil$Accessor.init(DataObjectUtil.java:2017)
at org.apache.tuscany.sdo.util.DataObjectUtil$Accessor.create(DataObjectUtil.java:1932)
at org.apache.tuscany.sdo.util.DataObjectUtil$Accessor.create(DataObjectUtil.java:1926)
at org.apache.tuscany.sdo.util.DataObjectUtil.get(DataObjectUtil.java:776)
at org.apache.tuscany.sdo.impl.DataObjectImpl.get(DataObjectImpl.java:221)
at org.apache.tuscany.sdo.impl.DataObjectImpl.getString(DataObjectImpl.java:426)
at Test.main(Test.java:19)


why is it? who can help, appreciated first.