Index: /issm/trunk/src/c/DataSet/DataSet.cpp
===================================================================
--- /issm/trunk/src/c/DataSet/DataSet.cpp	(revision 4208)
+++ /issm/trunk/src/c/DataSet/DataSet.cpp	(revision 4209)
@@ -519,6 +519,14 @@
 
 	if(objects.size()){
+
+		/*Delete existing ids*/
+		xfree((void**)&sorted_ids);
+		xfree((void**)&id_offsets);
+
+		/*Allocate new ids*/
 		sorted_ids=(int*)xmalloc(objects.size()*sizeof(int));
 		id_offsets=(int*)xmalloc(objects.size()*sizeof(int));
+
+		/*Build id_offsets and sorted_ids*/
 		for(i=0;i<objects.size();i++){
 			id_offsets[i]=i;