Zugriffsverletzung ADSI, so was komisches hab ich noch nie..

[cherry]

Versuche zunächst mal ganz klein anzufangen:

Delphi-Quellcode:

procedure TForm1.Button3Click(Sender: TObject);
const
  ColCount = 3;
  ColNames : array[0..ColCount-1] of PWideChar = ('Name','Description','ADsPath');
var
  search: IDirectorySearch;
  ptrResult: Pointer;
  hr : HRESULT;
begin
  if SUCCEEDED(ADsGetObject(PWideChar('LDAP://DC=thun,DC=lan'), IDirectorySearch, Pointer(search))) then
  begin
    if SUCCEEDED(search.ExecuteSearch('(objectClass=organizationalUnit)',@ColNames,ColCount,ptrResult)) then
    begin
      hr := search.GetNextRow(ptrResult); // Zugriffsverletzung
    end;
  end;
end;

Und auch ...

Delphi-Quellcode:

procedure TForm1.Button3Click(Sender: TObject);
const
  ColCount = 3;
  ColNames : array[0..ColCount-1] of PWideChar = ('Name','Description','ADsPath');
var
  search: IDirectorySearch;
  ptrResult: Pointer;
  hr : HRESULT;
begin
  if SUCCEEDED(ADsGetObject(PWideChar('LDAP://DC=thun,DC=lan'), IDirectorySearch, Pointer(search))) then
  begin
    if SUCCEEDED(search.ExecuteSearch('(objectClass=organizationalUnit)',@ColNames,ColCount,ptrResult)) then
    begin
      hr := search.GetFirstRow(ptrResult); // Zugriffsverletzung
    end;
  end;
end;

Was mach ich denn falsch?