When run test I found, that the binding parameters of Update operation are missing and test fails.
During debug I found that is used SPARQLUpdateOperation object.
on HTTPUpdate.execute() -> HTTPRepositoryConnection .scheduleUpdate(HTTPUpdate update)
I suppose that, the reason is in its serialization in TransactionWriter.serialize(SPARQLUpdateOperation op, XMLWriter xmlWriter) who does not serialize the bindings.
Windows, apache-tomcat 7.0.27, java 1.7.0_17