Upgrade to Hardy Heron on Dell desktop

I tried this yesterday using the exact method (click Upgrade on Update Manager box) as worked perfectly for me on the MacBook. Although the installation seemed to go without problems, when I tried to boot to hardy, I got dropped to a BusyBox shell.
Unfortunately, I forgot to take note of exactly why it dropped me to a shell.
In any event, I decided to go ahead and re-install gutsy which went fairly trouble free so, at least now, I have a functioning computer.