Comment 10 for bug 448316

I had the same symptom: empty list in "Prepare partitions" page.
The reason in my case was that the disk was used, several years ago in a server with RAID configuration. Disks were updated to the server and old once were reused in old laptops. Everything worked fine until I needed to reinstall the laptop with Ubuntu 9.10. I do not know for sure, but I'll assume that the Ubuntu installer does not show "raw" disks which belongs to RAID configuration, but instead tries to show the RAID device. As in my case the "raw" disk was detected to be part of RAID, but there was no RAID configuration in the laptop the installer ended up to show empty list in "Prepare partitions" page.

So I would like to advice you to start Ubuntu 9.10 liveCD, start terminal and give command:
devkit-disks --dump
In case you see line
usage: raid
in your hard disk devices information lines, although the device is not part of RAID configuration, it may be that Ubuntu 9.10 detects some old RAID configurations from the disk. In my case I was able to remove this RAID configuration information from the disk by zeroing the last blocks of the disk. Be warned, this destroys data from the disk, thus use this only in case you want to reinstall to whole disk. (If you want to keep some old installations or partitions, this is not the way to do it!)
I wrote down the size of sda from the output of
cat /proc/partitions
Then I zeroed the end of the disk:
sudo dd if=/dev/zero of=/dev/sda bs=1024 skip=<the size of sda - 10> count=10

I would advice to include output of "devkit-disks --dump" to all problems related to "empty list in Prepare partitions page" symptom as it makes problem solving much easier.