FilterOnNodeFailure.scala

 val root = <numbers>
    <number>1</number>
   <number>2</number>
   <number>3</number>
</numbers>                                        

val root2= <numbers>
  {for (x<- 1 to 3) yield <number>{x}</number>}
</numbers>                                       

def find2(n:scala.xml.Node)=(n== <number>2</number>)                                                
 
 (root\"number").filter(find2)                    //> scala.xml.NodeSeq = NodeSeq(<number>2</number>)
 (root2\"number").filter(find2)   //> scala.xml.NodeSeq = NodeSeq()
 
 (root\"number").hashCode                         //> Int = 1598709610
 (root2\"number").hashCode                        //> Int = 1439920665

scala/scala-xml#25