Such problems with the install

[Sean Murphy]

Tried to do two Ubuntu installs this weekend, failed at both. One was 
the i386 iso on an AMD K6, the other was the PowerPC iso on a Pismo.

MD5 checksums fine, CD passes the installer's scan. I have downloaded 
each file twice from bittorrent and once from ubuntu.org.

On the AMD, in every case the installer failed at the 'install base 
system' step on kernel-image-2.6-386

in particular, /usr/sbin/mkinitrd: line 1: 32123 Segmentation fault     
mk cramfs /tmp/mkinitrd.31773/initrd /dev/fd/3 >/dev/null
Failed to create image

The powerbook is able to get through all of phase 1 of the install but 
then informs me processing has halted because there were too many 
errors.

Can anyone tell me if it is possible/probable for hardware failures to 
be causing these errors? Both of these systems have taken quite a lot 
of abuse--i just don't want to put more troubleshooting time in to them 
than is needed.

Thanks for any input.