This topic has been covered several times before, smoothpilot. Here's one of the message threads relating to this subject:
http://www.pprune.org/forums/showthr...ht=cabin+light
Rgds.
Q.
P.S. I'd be a little concerned if the lights went out automatically on a Boeing 767 or a 747 if the aircraft was simply in takeoff/landing configuration (the 767 does have an engine start electrical loadshedding process, but shouldn't otherwise shed electrical loads unless a generator has failed... or the aircraft is dumping fuel).