When you click the yellow pill button in the upper left corner of a window to minimize that window in Mac OS X or if you use ⌘ Cmd + M you might want to bring the application back. When cycling through running applications, including the minimised applications, using ⌘ Cmd + Tab you might expect to retrieve the application back.
This sequence on the other hand will bring wour application window.
1. Use ⌘ Cmd + Tab untill you find your application.
2. Before releasing ⌘ Cmd, press and hold ⌥ Alt
Other method is to hide application using ⌘ Cmd + H, then you can restore your window with ⌘ Cmd + Tab