When in full-screen mode with all panels hidden, the Flimstrip can be shown by hovering over a "up arrow" on the bottom of the screen.
Now when Lighroom is minimized using Win+D shortcut, and restored later, the "up arrow" to show the Filmstrip is gone until I cycle through to all the screen modes, and back to full-screen mode.
My system:
Win 7 64bit Ultimate
Dell Studio 1558 with i7, 1gb ATI Radion 5470 and 8gb RAM.