installer (in expert mode) does not successfully reboot to finish install

Binary package hint: debian-installer

In expert mode, when selecting "Finish the installation", there is a pause and then the expert menu list returns. Looking at the tty4 logs, it seems that something is done to cause /proc to be unmounted before it should be, failing other commands. Screenshot attached...

ProblemType: Bug
Architecture: amd64
CurrentDmesg:
 [ 30.193318] ppdev: user-space parallel port driver
 [ 58.145119] JBD: barrier-based sync failed on vda9:8 - disabling barriers
Date: Tue Oct 27 17:55:20 2009
DistroRelease: Ubuntu 9.10
Lsusb: Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
MemoryUsage:
 total used free shared buffers cached
 Mem: 504120 483044 21076 0 27332 206060
 -/+ buffers/cache: 249652 254468
 Swap: 369452 0 369452
Package: debian-installer (not installed)
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.31-14-generic root=UUID=d56066b0-4188-4d35-a0a0-47d6c2f1745d ro quiet splash
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: User Name 2.6.31-14.48-generic
SourcePackage: debian-installer
Uname: Linux 2.6.31-14-generic x86_64
XsessionErrors:
 (gnome-settings-daemon:1731): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
 (gnome-settings-daemon:1731): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
 (nautilus:1788): Eel-CRITICAL **: eel_preferences_get_boolean: assertion `preferences_is_initialized ()' failed
 (polkit-gnome-authentication-agent-1:1802): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed
dmi.bios.date: 01/01/2007
dmi.bios.vendor: QEMU
dmi.bios.version: QEMU
dmi.chassis.type: 1
dmi.modalias: dmi:bvnQEMU:bvrQEMU:bd01/01/2007:svn:pn:pvr:cvn:ct1:cvr: