Bug#494532: lenny di-2 on dell optiplex 755 fail disk detection
> Harddrive was not detected. I assume the installer is missing the
> driver for the chipset, Intel 82Q35 Express PT IDER Controller
> [8086:29b6] (rev 02)
I saw similar symptoms here. A glance at /var/log/syslog revealed that
the installer was not able to find libparted1.7-udeb. That package
seems to have been removed in favor of libparted1.8-udeb and the
images haven't been updated accordingly.
In this case, it would be a library issue, not a driver issue.