bad upgrade event

[Jude DaShiell]

I went and tried doing an upgrade from lenny to squeeze on a friend's 
computer who is located several states away from me.  Huge mistake!  As a 
result of that attempt, the packages situation can't be fixed not even 
with dpkg --configure -a and aptitude is disabled from working and apt-get 
-f install and apt-get -f remove can't do anything to help the situation. 
Grub also can't be upgraded since problems with the boot sector were 
found.  My friend has got pretty many files he can probably download again 
already on the system and I hope the burn script will work for him so he 
can at least burn those to DVD.  I recommended he get the system 
reinstalled by the person who built it for him originally.  I don't even 
think having taken gnome-desktop-environment off of that system before the 
upgrade attempt would have helped but it's too late to go back and 
experiment now.  Might there be any other things that I could do short of 
having a system reinstall that will break the upgrade jam?  I can't even 
downgrade to lenny at least with the tools I know about.