Originally Posted by Jeff Wills

Personally, I'd try to figure out what's making noise. Are the bearings spinning smoothly? If so, I'll bet something else is moving around- an issue with cartridge BB's since there are so many metal-to-metal interfaces that can move around.

I would remove the BB, clean the threads, clean the inside of the cups, clean the outside of the cartridge, and then reassemble with grease on all mating surfaces. If the noise goes away, you've fixed the problem. If the noise goes away then reappears, I'll bet there's a bit too much clearance between a couple parts. I would repeat the dissassembly/reassembly process, but use a layer of plumber's teflon tape in place of grease.

I went through this a couple years ago on a bike with a cartrige BB in an aluminum frame. It took a couple repetitions with grease before I tried teflon tape. It's been tight and noise-free for a couple years.