My PC is fairly old and the hardware is quite weak, but it runs unity 2D quite well and fast. But I have this only one problem. The close/minimize,maximize buttons dont appear When I open a application window (like writer,calc,etc) and the launcher(sidebar) disappears before the application opens. I notices however when the application opens with the launcher bar on the screen there is no problem. Also when i the buttons dont appear with i click the dash home and return to the window the buttons appear. Is this a bug? is there a fix to this?
Which theme do you use? Default (Ambience, Radience) or custom? For old hardware you may try gnome fallback or xfce and cardapio menu as alternative to unity-dash.