Help...elevator does not move [SOLVED]

[grimley]

I am playing Machinarium on an iMac. I have reached the indoor elevator, inserted the missing bulb, lighted the bulbs in a star pattern, but the elevator does not move, as the walkthrough suggests. When I lighted the bulb, the screen jumped to a more complex pattern with another empty socket. Am I missing something, or is this a glitch in the game? Stumped.

[Alex]

You're missing something.  There should be a bulb in every socket.

[grimley]

Thank you. I tried it again yesterday and it finally worked!