diff --git a/hurricane/src/hurricane/hurricane/Commons.h b/hurricane/src/hurricane/hurricane/Commons.h
index a3b79b95..423f3e4c 100644
--- a/hurricane/src/hurricane/hurricane/Commons.h
+++ b/hurricane/src/hurricane/hurricane/Commons.h
@@ -33,6 +33,7 @@
 #include <cstdio>
 #include <cassert>
 
+#include <tr1/memory>
 #include <string>
 #include <list>
 #include <set>
@@ -83,6 +84,27 @@ namespace Hurricane {
 
 
 
+  // x-------------------------------------------------------------x
+  // |                shared_ptr<> support for DBo                 |
+  // x-------------------------------------------------------------x
+
+
+  template<typename DboType>
+  class DboDestroy {
+    public:
+      inline void operator() ( DboType* dbo ) { dbo->destroy(); }
+  };
+
+
+  template<typename DboType>
+  class dbo_ptr : public tr1::shared_ptr<DboType> {
+    public:
+      dbo_ptr ( DboType* dbo ) : tr1::shared_ptr<DboType>(dbo,DboDestroy<DboType>()) { }
+  };
+
+
+
+
   // x-------------------------------------------------------------x
   // |                   Miscellaneous Utilites                    |
   // x-------------------------------------------------------------x
diff --git a/hurricane/src/hviewer/CellViewer.cpp b/hurricane/src/hviewer/CellViewer.cpp
index 2cf15215..a01f1779 100644
--- a/hurricane/src/hviewer/CellViewer.cpp
+++ b/hurricane/src/hviewer/CellViewer.cpp
@@ -331,8 +331,10 @@ namespace Hurricane {
 
   void  CellViewer::setCell ( Cell* cell )
   {
+    Name cellName = (cell) ? cell->getName() : "empty";
+
     list< shared_ptr<CellWidget::State> >::iterator istate
-      = find_if ( _cellHistory.begin(), _cellHistory.end(), CellWidget::FindStateName(cell->getName()) );
+      = find_if ( _cellHistory.begin(), _cellHistory.end(), CellWidget::FindStateName(cellName) );
 
     if ( istate != _cellHistory.end() ) {
       emit stateChanged ( *istate );