Backup light not working?

For some reason my backup lights are again not working. Not sure what the hell is going on. The stealership adjusted the tranny linkage they told me when they were looking at the problem I'm having with it. Same evening reversing noticed they didn't seem to come on. Checked them the next day and sure enough, they're not coming on. [I can still operate manually though for now]
What wires should I be looking at for this? [as in the ones that are by the back of the engine by the NSS wiring] and could it be my NSS is out of adjustment somehow and I just need to do a simple re-placement? The NSS isn't giving me any problems per say, as it'll start as usual after cleaning it a few months back.
Any suggestions what to try is greatly appreciated, as I have to have this thing safetied in the coming weeks.
TIA

First things first, check your fuses and bulbs. Hopefully you won't have to take the nss off. If it is the nss, be sure and clean it up right. There's a write up on http://jeepin.com . If it's your first time taking off the nss, you're going to have alot of "fun". The first time I took off a nss, i had a "great" time.

Bulbs I know are good. They're hooked up as well to my rear lighting, which is what triggered me to notice them not on in reverse. Will put a new fuse in just for sake of arguement, as it appears to be fine.
I've already done the NSS as per that write up. Just wondering if it is a bit off, and needs to be adjusted at all or such. Only thing I can think of why it suddenly stopped working. Only thing that's been done was the stealership adjusting the linkage for the tranny.