[racket] Scribble Planet problem

Hi,

I've developed a small library that I would like to put on Planet, but
when I create the planet package and test-install it using raco planet
fileinject, my scribble documentation messes up the Racket docs. My
docs are listed in the documentation main page and can be viewed, but
just before the entry something is displayed in red (sorry, don't recall
what exactly it said), and the global search function ceases to work.
Deinstalling the local package with raco planet remove fixes the
documentation again.

Here is the start of my file manual.scrbl in the main directory of the
package:

#lang scribble/manual
@(require
    (for-label racket
               "file-utils.rkt"))

@defmodule[(planet erast/file-utils)]

Is there something wrong here? The documentation compiles without error
and shows up fine in my browser if I push the Scribble HTML button in
DrRacket.

Sorry if I've missed something obvious, it's the first time I've been
using Scribble. Any help very much appreciated.

Best,

Erich