ProgressBar: call of service not succeeded

Hi All,

When I try to set value/text ProgressBar property in my event handle...sometimes it goes in error with this message

<b>call of service not succeeded : at SAPbouiCOM.ProgressBarClass.set_Value(Int32 pVal) at .. etc..</b>

or

<b>call of service not succeeded : at SAPbouiCOM.ProgressBarClass.set_Text(String pVal) at .. etc..</b>

this is the code:

Private Sub _Procedure_Elaboration(ByVal countAs Integer, ByVal totalCount As Integer) Handles _Procedure.Elaboration

        If _ProgressCreated = False Then
            _pBar = myApp.StatusBar.CreateProgressBar(String.Empty, totalCount , False)
           _ProgressCreated = True
        End If

        _pBar.Text = String.Format("Elaboration {0}/{1}: ", count, totalCount)
        _pBar.Value = count

End Sub

thanks a lot

best regards