one Button bug?!?

[mb]

i have a problem to display one button - when i have 2 buttons, it
works fine...


whatever i use(window, panel, ..)


it this a bug?!?


$window = new PhpExt_Window();
$window->setTitle("title window")
->setWidth($this->setWindowWidth)
->setHeight($this->setWindowHeight)
->setMinWidth(300)
->setMinHeight(200)
->setLayout(new PhpExt_Layout_FitLayout())
->setResizable(true)
->setCloseAction(PhpExt_Window::CLOSE_ACTION_HIDE)
->setPlain(true)
->setBodyStyle("padding:5px")
->setButtonAlign(PhpExt_Ext::HALIGN_CENTER);

$window->addButton(PhpExt_Button::createTextButton("Cancel"));
$window->addButton($this->_SubmitButton('Save', 'Saving Data...'));