diff -u -r1.26 -r1.27
--- MCParticleImpl.cc	27 May 2005 07:55:55 -0000	1.26
+++ MCParticleImpl.cc	23 Feb 2006 14:44:18 -0000	1.27
@@ -200,8 +200,11 @@

 
     checkAccess("MCParticleImpl::addParent") ;
 

-//     MCParticle** pD = new (MCParticle*)  ;
-//     *pD = parent ;

+
+    if(  std::find(  _parents.begin(), _parents.end(),  parent ) != _parents.end() )
+      return ; // parent already exists in list
+
+

     _parents.push_back( parent ) ;
 
     MCParticleImpl* mom = dynamic_cast<MCParticleImpl*>( parent ) ;