weird problem rebuilding udeb Packages file

[Yannick Menager]

I have a weird problem.

I've had to recreate the Packages file for the udebs in order to 
customize an installer CD (so by running apt-ftparchive -c $APTCONF 
generate /opt/apt-ftparchive/apt-ftparchive-udeb.conf).

The problem is that the Packages file that is generated comes in a 
different order than the one on the CD, and that's strangely breaking 
the installer by making it try to use PPPOE when it shouldn't (!?). I 
wrote a small script that re-orders the file in the same order than the 
original one, and that fixes the problem. Any idea what's going on ?

I'm using 
http://archive.ubuntu.com/ubuntu/indices/override.hardy.main.debian-installer 
as well as

Dir {
  ArchiveDir "/opt/cd-image/";
};

TreeDefault {
  Directory "pool/";
};

BinDirectory "pool/main" {
  Packages "dists/hardy/main/debian-installer/binary-i386/Packages";
  BinOverride "/opt/indices/override.hardy.main.debian-installer";
};

BinDirectory "pool/restricted" {
  Packages "dists/hardy/restricted/debian-installer/binary-i386/Packages";
  BinOverride "/opt/indices/override.hardy.restricted.debian-installer";
};

Default {
  Packages {
    Extensions ".udeb";
    Compress ". gzip";
  };
};

Contents {
  Compress "gzip";
};