diff --git a/EgtMachKernel.rc b/EgtMachKernel.rc
index 530556c..5e0760e 100644
Binary files a/EgtMachKernel.rc and b/EgtMachKernel.rc differ
diff --git a/Machine.cpp b/Machine.cpp
index cdbefa1..d19033c 100644
--- a/Machine.cpp
+++ b/Machine.cpp
@@ -690,11 +690,12 @@ Machine::EnableHeadInSet( const string& sHead)
    const STRVECTOR& vsHSet = GetHSet( sHead) ;
    if ( vsHSet.empty())
       return false ;
-  // spengo tutte le teste tranne questa
+  // spengo tutte le teste dell'insieme tranne questa
    for ( size_t i = 0 ; i < vsHSet.size() ; ++ i) {
       int nH = GetGroup( vsHSet[i]) ;
       bool bShow = ( vsHSet[i] == sHead) ;
-      m_pGeomDB->SetStatus( nH, ( bShow ? GDB_ST_ON : GDB_ST_OFF)) ;
+      m_pGeomDB->SetMode( nH, ( bShow ? GDB_MD_STD : GDB_MD_HIDDEN)) ;
+      //m_pGeomDB->SetStatus( nH, ( bShow ? GDB_ST_ON : GDB_ST_OFF)) ;
    }
    return true ;
 }
diff --git a/MachineHeads.cpp b/MachineHeads.cpp
index 1a4b6b0..6985669 100644
--- a/MachineHeads.cpp
+++ b/MachineHeads.cpp
@@ -178,7 +178,8 @@ Machine::ResetHeadSet( const string& sHead)
          pExit->SetTool( "") ;
       }
      // visualizzo solo la prima testa
-      m_pGeomDB->SetStatus( nHdGrp, ( i == 0 ? GDB_ST_ON : GDB_ST_OFF)) ;
+      m_pGeomDB->SetMode( nHdGrp, ( i == 0 ? GDB_MD_STD : GDB_MD_HIDDEN)) ;
+      //m_pGeomDB->SetStatus( nHdGrp, ( i == 0 ? GDB_ST_ON : GDB_ST_OFF)) ;
    }
    return true ;
 }
\ No newline at end of file
diff --git a/Simulator.cpp b/Simulator.cpp
index 1168476..d5c94d5 100644
--- a/Simulator.cpp
+++ b/Simulator.cpp
@@ -314,8 +314,8 @@ Simulator::UpdateTool( bool bForced)
         // ripristino l'utensile corrente
          m_pMchMgr->TdbSetCurrTool( m_sTool) ;
       }
-     // se cambierà e non forzato (inizio), scarico l'utensile corrente
-      if ( sTool != m_sTool  &&  ! bForced) {
+     // se cambierà ed esiste il corrente, lo scarico
+      if ( sTool != m_sTool  &&  ! m_sTool.empty()) {
         // eventuale lancio script per scarico utensile
          if ( ! OnToolDeselect( sTool, sHead, nExit, sTcPos))
             return false ;
@@ -344,9 +344,12 @@ Simulator::UpdateTool( bool bForced)
      // recupero i dati
       string sTool ; string sHead ; int nExit ; string sTcPos ;
       pDisp->GetToolData( sTool, sHead, nExit, sTcPos) ;
-     // eventuale lancio script per scarico utensile
-      if ( ! OnToolDeselect( sTool, sHead, nExit, sTcPos))
-         return false ;
+     // se cambierà ed esiste il corrente, lo scarico
+      if ( sTool != m_sTool  &&  ! m_sTool.empty()) {
+        // eventuale lancio script per scarico utensile
+         if ( ! OnToolDeselect( sTool, sHead, nExit, sTcPos))
+            return false ;
+      }
      // carico l'utensile
       if ( ! m_pMchMgr->SetCalcTool( sTool, sHead, nExit))
          return false ;
@@ -452,7 +455,7 @@ Simulator::FindAndManageOperationStart( bool bFirst, int& nStatus)
       Machining* pMch = GetMachining( m_pGeomDB->GetUserObj( m_nOpId)) ;
       if ( pMch != nullptr  &&  ! pMch->IsEmpty()) {
         // aggiorno utensile e assi conseguenti
-         if ( ! UpdateTool()) {
+         if ( ! UpdateTool( bFirst)) {
             nStatus = MCH_SIM_ERR ;
             return false ;
          }