diff --git a/Icarus/ImportPanel/ImportPanelVM.vb b/Icarus/ImportPanel/ImportPanelVM.vb
index 00c5747..4b5b7e6 100644
--- a/Icarus/ImportPanel/ImportPanelVM.vb
+++ b/Icarus/ImportPanel/ImportPanelVM.vb
@@ -364,6 +364,8 @@ Public Class ImportPanelVM
                EgtSetMode(nFrameId, GDB_MD.LOCKED)
             End If
             EgtSetInfo(nReferenceLayerId, KEY_REFERENCE, PrintSolidEntity.Reference)
+            ' appoggio il pezzo sulla tavola
+            EgtMove( nPartId, New Vector3d(0, 0, -b3PrintSolid.Min.z))
             ' lo aggiungo a lista pezzi 
             Dim sFilePath As String = ""
             EgtGetInfo(m_nImportedPartId, FILE_PATH, sFilePath)
diff --git a/Icarus/SliceManager/SliceManagerVM.vb b/Icarus/SliceManager/SliceManagerVM.vb
index eb5251e..74d23ff 100644
--- a/Icarus/SliceManager/SliceManagerVM.vb
+++ b/Icarus/SliceManager/SliceManagerVM.vb
@@ -56,6 +56,8 @@ Public Class SliceManagerVM
                Return "Calculating Feed & Speed..."
             Case CalcSteps.GENERATE
                Return "Generating..."
+            Case Else
+               Return ""
          End Select
       End Get
    End Property
diff --git a/Icarus/SliderManager/SliderManagerVM.vb b/Icarus/SliderManager/SliderManagerVM.vb
index 54b8308..69e6189 100644
--- a/Icarus/SliderManager/SliderManagerVM.vb
+++ b/Icarus/SliderManager/SliderManagerVM.vb
@@ -13,12 +13,13 @@ Public Class SliderManagerVM
       FROM_SELECTED = 3
    End Enum
 
-   Private m_nLayerIndex As Integer = 1
+   Private m_nLayerIndex As Integer = 0
    Public Property nLayerIndex As Integer
       Get
          Return m_nLayerIndex
       End Get
       Set(value As Integer)
+         If IsNothing(Map.refTopPanelVM.SelPart) Then Return
          Select Case m_nSelViewSlider
             Case ViewSliderType.ONLY_SELECTED
                ' se diverso da nullo nascondo precedente
diff --git a/Icarus/StartMachPanel/StartMachPanelVM.vb b/Icarus/StartMachPanel/StartMachPanelVM.vb
index 06f6435..4e6a6ef 100644
--- a/Icarus/StartMachPanel/StartMachPanelVM.vb
+++ b/Icarus/StartMachPanel/StartMachPanelVM.vb
@@ -460,8 +460,11 @@ Public Class StartMachPanelVM
    ''' </summary>
    Public Sub Point(ByVal param As Object)
       If Map.refSceneHostVM.MainController.GetStep <> 0 Then Return
-      Dim nNewStartLayerId As Integer = EgtCreateGroup(m_nPartId)
-      EgtSetName(nNewStartLayerId, LAY_NEWSTART)
+      Dim nNewStartLayerId As Integer = EgtGetFirstNameInGroup( m_nPartId, LAY_NEWSTART)
+      If nNewStartLayerId = GDB_ID.NULL Then
+         nNewStartLayerId = EgtCreateGroup(m_nPartId)
+         EgtSetName(nNewStartLayerId, LAY_NEWSTART)
+      End If
       EgtSetCurrPartLayer(m_nPartId, nNewStartLayerId)
       'InitCommand(True)
       If Map.refSceneHostVM.MainController.ExecuteCommand(Controller.CMD.POINT) Then
@@ -490,8 +493,11 @@ Public Class StartMachPanelVM
    ''' </summary>
    Public Sub Line2P(ByVal param As Object)
       If Map.refSceneHostVM.MainController.GetStep <> 0 Then Return
-      Dim nNewStartLayerId As Integer = EgtCreateGroup(m_nPartId)
-      EgtSetName(nNewStartLayerId, LAY_NEWSTART)
+      Dim nNewStartLayerId As Integer = EgtGetFirstNameInGroup( m_nPartId, LAY_NEWSTART)
+      If nNewStartLayerId = GDB_ID.NULL Then
+         nNewStartLayerId = EgtCreateGroup(m_nPartId)
+         EgtSetName(nNewStartLayerId, LAY_NEWSTART)
+      End If
       EgtSetCurrPartLayer(m_nPartId, nNewStartLayerId)
       Map.refSceneHostVM.MainController.SetContinue()
       If Map.refSceneHostVM.MainController.ExecuteCommand(Controller.CMD.LINE2P) Then