debootstrap says Packages was corrupt

[Neale Banks <neale@lowendale.com.au>]

Hi,

I've been, mostly successfully, customising the etch Netinst with
preseeding.

But... I added a few more debs to the pool and rebuilt Packages[.gz] with
apt-ftparchive - now debootstrap complains:
"Warning: file:///cdrom/dists/etc/main/binary-i386/Packages.gz was corrupt"
and
"Warning: file:///cdrom/dists/etc/main/binary-i386/Packages was corrupt"
and
"Warning: Failure trying to run: chroot /target mount -t proc proc /proc"

In /var/log/syslog we find:

==============================8<==============================
[...]
May 18 00:29:36 main-menu[1230]: INFO: Falling back to the package description for ai-choosers 
May 18 00:29:36 main-menu[1230]: INFO: Menu item 'base-installer' selected 
May 18 00:29:38 debootstrap: /target/var/lib/apt/lists/debootstrap.invalid_dists_etch_main_binary-i386_Packages: No such file or directory
May 18 00:29:38 debootstrap: /target/var/lib/apt/lists/debootstrap.invalid_dists_etch_main_binary-i386_Packages: No such file or directory
May 18 00:29:38 debootstrap: ar: 
May 18 00:29:38 debootstrap: Short read
May 18 00:29:38 debootstrap: 
May 18 00:29:38 debootstrap: zcat: 
May 18 00:29:38 debootstrap: Short read
May 18 00:29:38 debootstrap: 
May 18 00:29:38 debootstrap: chroot: 
May 18 00:29:38 debootstrap: cannot execute mount
May 18 00:29:38 debootstrap: : No such file or directory
May 18 00:32:26 init: Starting pid 1192, console /dev/vc/2: '/bin/sh'
==============================8<==============================

Any pointers to what would make debootstrap complain like this?

Thanks,
Neale.