Patch provided by Lauren Foutz. See:
https://community.oracle.com/thread/4093422

--- dbxml-6.1.4-orig/dbxml/src/dbxml/query/ParentOfChildJoinQP.cpp
+++ dbxml-6.1.4/dbxml/src/dbxml/query/ParentOfChildJoinQP.cpp
@@ -139,28 +139,16 @@ bool ParentOfChildIterator::doJoin(Dynam
 
 	// Invarient 4: When ancestorStack_ is empty we can output the
 	// buffered results_, since any more results will come after them in
 	// document order.
 
 	while(true) {
 		context->testInterrupt();
 
-		/* 
-		 * If current parent's node level already be larger than
-		 * childen's, abandon current parent and move to next one.
-		 */
-		if (parents_ != NULL && 
-		    parents_->getNodeLevel() > children_->getNodeLevel()) {
-			if(!parents_->next(context)) {
-				delete parents_;
-				parents_ = 0;
-			}
-		}
-
 		int cmp = parents_ == 0 ? -1 : isDescendantOf(children_, parents_, /*orSelf*/false);
 		if(cmp < 0) {
 			if(!ancestorStack_.empty()) {
 				// We've found the closest ancestor - is it a parent?
 				if(ancestorStack_.back()->getNodeLevel() == (children_->getNodeLevel() - 1)) {
 					// Maintain invarient 3
 					if(results_.empty() || NodeInfo::compare(results_.back(), ancestorStack_.back()) < 0)
 						results_.push_back(ancestorStack_.back());