Setup.exe ignores some setup.ini entries

[Bob]

I want to add my own category for some of the Cygwin packages so I'm
investigating modifying the setup.ini file (this seems like the best way
to do it, please tell me if you think otherwise).

I've noticed that although the setup.ini file has entries for packages
such as the XFree86 packages and apache (for example), they aren't read
by setup.exe.  I know this because they don't show up if I rename the
"release" folder to something else.  Without the renaming they show up
just fine.

Can anyone explain to me why this is the case? 

My goal is to create a custom distribution of Cygwin for internal use. 
I know there were threads about this idea earlier but they didn't seem
to go anywhere.  I'd be interested if anyone's done this successfully.

Thanks,
Bob