Guide lines for using Quark to create DIFs?

I deleted the message from my previous post as I had the wrong title.

Hi all!
I'm building a small interior in Quark and everything was just fine, tested my interior several times and was getting the hang of it.

As soon as I closed the whole thing off and added lights, I started seeing light leaks all over the place.
I thought it was my omni lights I was using so I took them all out, cut a hole for a window and still got them all over with the ambient light.

I saw some info suggesting to tag and glue all the faces, so I did that and no dice.
I used the grid so everthing is lined up.
I also saw some posting somewhere that the "walls" have to be at least 16 Quark units thick, mine are 8.

I tried changing some of them to 16 and sure enough it works, but I don't want to have to switch my whole map. Plus the walls look odd that thick.

Are there any tutorials or anything specifically on building maps for Torque that would go over the guide lines for wall thickness, talk about the tag & glue, etc? I've seen a bunch of tutorials, but nothing that touches on that stuff.

I had to dig through the forums for that stuff above and it's still giving me problems. It would be nice if there were one central area for that stuff.

Thanks for any info.