15+ packages fail to update when using update-manager on ubuntu 8.04 alpha 4

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=8.04
DISTRIB_CODENAME=hardy
DISTRIB_DESCRIPTION="Ubuntu hardy (development branch)"
python-apt: 0.7.4ubuntu6
System: Dell Inspiron 5100 (4-5 year old laptop) / 384 MB Ram / P4 2.4GHz / touchpad (mouse)

Steps to reproduce:
1. Download the 8.04 alpha 4 iso from cdimage.ubuntu
2. Do a full install (use entire disk via partitioning).
3. When asked for installing updates, install all pending updates.
4. Two hours later (after downloading), lots of application updates seem to have failed (I have right now about 10-11 application bug report tabs at launchpad open !!!).

Note: This is my second install on this laptop. Yesterday I did a complete install of ubuntu 7.10 from a DVD and did an update to 8.04 ... and that failed with exactly the same error while updating (python-apt / update-manager .... etc... ). In fact after the update, synaptic / apt-get wouldnt even start properly... basically forcing me to try this route... which also failed. I have intentionally not mentioned python-apt in the bug report title, since it seems that something basic failed due to which lots of applications failed to update.... I am listing all the applications that failed for me today:
update-notifier 0.70.4
ubuntu-desktop 1.93
python-apt 0.7.4ubuntu6
gnome-app-install 0.5.2.3-0ubuntu1
update-manager 1:0.87.9
update-manager-core 1:0.87.9
unattended-upgrades 0.26ubuntu1
jockey-common 0.2-0ubuntu5
software-properties 0.62ubuntu1
software-properties-gtk 0.62ubuntu1
apport 0.102
apport-gtk 0.102
python-apport 0.102
python-launchpad-bugs 0.2.27
jockey-gtk 0.2-0ubuntu5
software-properties-gtk 0.62ubuntu1

Hope it helps....

ProblemType: Package
Architecture: i386
Date: Wed Feb 20 01:09:58 2008
DistroRelease: Ubuntu 8.04
ErrorMessage: subprocess post-installation script returned error exit status 1
Package: python-apt 0.7.4ubuntu6
PackageArchitecture: i386
SourcePackage: python-apt
Title: package python-apt 0.7.4ubuntu6 failed to install/upgrade: subprocess post-installation script returned error exit status 1
Uname: Linux neo 2.6.24-8-generic #1 SMP Thu Feb 14 20:40:45 UTC 2008 i686 GNU/Linux