prompt to remove cryptsetup on an encrypted LVM install during end user setup

Precise Ubuntu Alternate 20120325

TEST CASE
1. Install Ubuntu Alternate in OEM mode
2. At the partitioning step select "Encrypted LVM"
3. Finish the first phase of the installation, reboot
4. Login as OEM, prepare for shipping and reboot
5. Proceed with end user setup

ACTUAL RESULT:
At the end of the end used setup, there is a debconf prompt that asks for removal of cryptsetup and the option is selected by default.
If the user keeps the default, the resulting system doesn't boot.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: oem-config (not installed)
ProcVersionSignature: Ubuntu 3.2.0-20.32-generic 3.2.12
Uname: Linux 3.2.0-20-generic x86_64
ApportVersion: 1.95-0ubuntu1
Architecture: amd64
Date: Mon Mar 26 15:54:57 2012
InstallCmdLine: file=/cdrom/preseed/ubuntu.seed vga=788 initrd=/install/initrd.gz quiet -- oem-config/enable=true
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120325)
ProcEnviron:
 TERM=xterm
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)