it is totally normal in late flowering for the older fan leaves to die off. i just let them die and fall, then just keep the floor clean. dead leaves are a perfect site for mold to grow so don't let them stay on the floor.

btw when you say 150watt cfls do you mean the big horticultural bulbs or the 42watters that say "same as a 150" on the box. if they are the 42's use that number when describing your grow so others won't be confused an can help you better. i'm asking because there seems to be alot of confusion about the 42's lately, there have been a few threads dedicated to the subject recently.