[racket] scribble and require

Having some Scribble difficulties.  I've got a collection with several source files.  Everything defined in the "main" source file shows up correctly in the help page, but things defined in the other source files (which are all require'd by the main one) show up underlined in red, not as functioning hot-links, and "raco setup" complains about them:
raco setup: WARNING: undefined tag in picturing-programs/doc.scrbl:
raco setup:  ((lib "picturing-programs/tiles.rkt") rotate-cw)
raco setup:  ((lib "picturing-programs/tiles.rkt") rotate-ccw)
...



main.rkt looks like 
#lang racket/base
(require 2htdp/universe
	2htdp/image
         htdp/error
         picturing-programs/tiles
	 picturing-programs/io-stuff
         etc. etc. etc.)
(provide (all-from-out picturing-programs/tiles)   ; includes all-from-out 2htdp/image, plus a few simple add-ons
         (all-from-out picturing-programs/io-stuff) ; includes with-{input-from,output-to}-{string,file}, with-io-strings
         (all-from-out 2htdp/universe)
         (all-from-out 2htdp/image)
	 etc. etc.)
...



doc.scrbl looks like
#lang scribble/doc
@(require 
  scribble/manual
  (for-label racket
             picturing-programs/main
             picturing-programs/io-stuff
	     picturing-programs/tiles
             2htdp/image
             2htdp/universe
             etc. etc.
             ))
@; teachpack["picturing-programs"]{Picturing Programs}
@title{Picturing Programs Teachpack}
@author{Stephen Bloch}
@defmodule[picturing-programs]
@section{Examples to figure out Scribble issues}
This is a reference to the @racket[list] function (good link; defined in racket).
Now a reference to @racket[triangle] (good link; defined in 2htdp/image),
and @racket[show-it] (good link, defined in main.rkt),
and @racket[crop-top] (underlined in red, not a link, defined in tiles.rkt), 
and @racket[map-image] (underlined in red, not a link, defined in map-image.rkt),
and @racket[with-input-from-url] (underlined in red, not a link, defined in io-stuff.rkt).
...


I must be missing something very basic.


Stephen Bloch
sbloch at adelphi.edu