Oh weird :O Think you could send me a screenshot or something of it? Do you know what videocard / driver you're using? Fairly certain I'm just running the Mesa driver on my Linux Mint machine with an ancient Intel HD4000.
Another possibility is that the game just isn't putting a light object on top of the module in the first place, or rendering it for some reason. Like a max-number of lights the game will bother drawing or something if you have a massive base? Will investigate :)