diff --git a/include/maskfld.cpp b/include/maskfld.cpp
index b3c437165..b6d4eca54 100755
--- a/include/maskfld.cpp
+++ b/include/maskfld.cpp
@@ -374,18 +374,19 @@ void TMask_field::construct(TScanner& scanner, WINDOW parent)
   
   scanner.popkey();                 // BEGIN
 #ifdef DBG 
+  const TMask& m = mask();
+
   if (scanner.key() != "BE")          
   {
-    NFCHECK("Testata errata o BEGIN mancante nel campo %d", _ctl_data._dlg);
+    NFCHECK("Testata errata o BEGIN mancante nel campo %d della maschera", 
+            _ctl_data._dlg, (const char*)m.source_file());
     scanner.push();
   }
   if (_ctl_data._dlg > 0)
   {              
-    const TMask& m = mask();
-    for (int f = m.fields()-1; f >= 0; f--)
+    FOR_EACH_MASK_FIELD(m, i, mf)
     {                                       
-      const TMask_field& mf = m.fld(f);
-      if (mf.dlg() == _ctl_data._dlg && mf.parent() == parent)
+      if (mf->dlg() == _ctl_data._dlg && mf->parent() == parent)
         NFCHECK("Esistono due campi con identificatore %d", _ctl_data._dlg);
     }
   }      
diff --git a/include/msksheet.cpp b/include/msksheet.cpp
index 5c389818e..04e607fbd 100755
--- a/include/msksheet.cpp
+++ b/include/msksheet.cpp
@@ -1267,7 +1267,7 @@ bool TSpreadsheet::event_handler(XI_OBJ* itf, XI_EVENT *xiev)
   case XIE_SELECT:
     if (xiev->v.xi_obj->type == XIT_ROW)
     {          
-      _check_enabled = FALSE;    
+      _check_enabled = false;    
       refused = TRUE;
 
       if (!test_focus_change())
@@ -1309,33 +1309,33 @@ bool TSpreadsheet::event_handler(XI_OBJ* itf, XI_EVENT *xiev)
       }
       else
       {
-        TMask & sm = owner().sheet_mask();
+        TMask& sm = owner().sheet_mask();
         const int button_pos = sm.id2pos(FIRST_FIELD-1);
         if (button_pos >= 0)
         {       
           TMask_field& button = sm.fld(button_pos);  
           if (button.active())
           { 
+            button.disable(); // Impedisce che un doppio click indesiderato abbia effetto
             if (!_row_dirty)                      
             {
               notify_change();                  
               _row_dirty = _cell_dirty = FALSE;
-              for (int i = sm.fields() - 1; i >= 0; i--)
-                sm.fld(i).set_dirty(FALSE);
-            }
-          
+              FOR_EACH_MASK_FIELD(sm, i, fld)
+                fld->set_dirty(false);
+            }     
             button.on_hit();   
             if (sm.dirty())
             {
               _row_dirty = TRUE;
               mask2str(_cur_rec);  
             }
-
+            button.enable();
           }
           owner().highlight();
         }        
       }  
-      _check_enabled = TRUE;    
+      _check_enabled = true;
     }    
     break;
   case XIE_DBL_CELL: