ufw couldn't be removed when ipv6 is turned off

Binary package hint: ufw

IPv6 is turned of in the system, with to following line in /etc/modprobe.d/aliases:
alias net-pf-10 off #ipv6

Release:
root@ubuntu-desktop:/etc/rcS.d# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu intrepid (development branch)
Release: 8.10
Codename: intrepid

Error:
root@ubuntu-desktop:/etc/rcS.d# aptitude purge ufw
Reading package lists... Done
Building dependency tree
Reading state information... Done
Reading extended state information
Initializing package states... Done
The following packages will be REMOVED:
  ufw{p}
0 packages upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
Need to get 0B of archives. After unpacking 0B will be used.
Do you want to continue? [Y/n/?] y
Writing extended state information... Done
(Reading database ... 106880 files and directories currently installed.)
Removing ufw ...
Purging configuration files for ufw ...
ip6tables v1.4.0: can't initialize ip6tables table `filter': Address family not supported by protocol
Perhaps ip6tables or your kernel needs to be upgraded.
dpkg: error processing ufw (--purge):
 subprocess post-removal script returned error exit status 3
Errors were encountered while processing:
 ufw
E: Sub-process /usr/bin/dpkg returned an error code (1)

Solution is to enable ipv6 temporary and do modprobe ipv6, so ip6tables can be executed when removing the software.

ProblemType: Package
Architecture: i386
Dependencies:

DistroRelease: Ubuntu 8.10
ErrorMessage: subprocess post-removal script returned error exit status 3
Package: ufw None
PackageArchitecture: all
SourcePackage: ufw
Title: package ufw None failed to install/upgrade: subprocess post-removal script returned error exit status 3
Uname: Linux 2.6.27-4-generic i686