diff -u -r1.3 -r1.4
--- SIOVertex.java	17 Oct 2007 02:06:23 -0000	1.3
+++ SIOVertex.java	21 May 2010 10:55:24 -0000	1.4
@@ -18,7 +18,7 @@

 /**
  *
  * @author Tony Johnson

- * @version $Id: SIOVertex.java,v 1.3 2007/10/17 02:06:23 tonyj Exp $

+ * @version $Id: SIOVertex.java,v 1.4 2010/05/21 10:55:24 grefe Exp $

  */
 class SIOVertex extends BaseVertex
 {

@@ -41,7 +41,7 @@

       for (int i=0; i<n; i++) 
       {
          Float f = in.readFloat();

-         if (!f.isNaN()) parameters.put(parameterNames[i],Double.valueOf(f));

+         if (!f.isNaN() && parameterNames != null) parameters.put(parameterNames[i],Double.valueOf(f));

       }
       recPRef = in.readPntr();
       _aParticle = null;