This is a link for youtube movie I make how the light in my 767 are working
If yours position ,beacon light  ... working correctly please tell me what the setting you running and what directX do you use

http://www.youtube.com/watch?v=tV1QrXk2bk0&feature=channel_page

My comp spec and setting
intel Q 6600 2,4
4gb ram
ge force 8800 gtx 768 mb latest driver installed
Fsx with sp2 not from fs accelerator
saitek yoke

Chris