Can not close Port after OnNoCarrier

I try to connect a remote modem with VaModem.

In case there is no carrier, I want to close the assigned Comport, but the program is hanging than.
 
My code looks like the following:
 
VaModem1.Dial(PhoneNumber);
 
procedure TForm1.VaModem1NoCarrier(Sender: TObject);
begin
  case vaModem1.ModemAction of
    maDial: vaModem1.Cancel;
  end;
  VaModem1.Hangup(true);
  VaModem1.Active := false;
  VaComm1.Close;              //here the program is hanging!!!
end;
 
Can anybody help?
Juergen