Why installer don't detect all disks ?

[Bruno Costacurta]

Hello,

I have a PC with three disks and want to install Fedora on a specific disk / 
partition.

/dev/sda --> Debian (existing)
/dev/sdb --> LVM used by Debian (existing)
/dev/sdc --> for Fedora-9 (new)

However Fedora installer detect only one disk.
So I used Knoppix to prepare a disk + partition for Fedora on /dev/sdc (to 
ease the job for the Fedora installer who looks lost with my disk 
detection...) however Fedora continues to detect only one disk (and no the 
one I intented to use for Fedora..)

Why Fedora installer cannot detect all the physical disks (all other distros 
or tools like gparted via Knoppix detect them correctly) ?
I tried Custom layout but got same uncomplete result.

How to install Fedora without the default installer + druid ?

thanks for any clue
Bye,
Bruno