Today I went at a friend's to help her set up a new PC in a dual boot configuration (Windows XP, which was already installed, and Kubuntu 8.04).
XP came preinstalled so I burned a CD with Kubuntu 8.04 and booted from it... just to find out that there was no normal way of detecting the HDD as device. Indeed,
sudo fdisk -l
showed nothing at all. Also, in dmesg there were some errors regarding an ATA port error.
So I booted back in XP and saw the HDD model was a HD502IJ Samsung on SATA that just might pose boot problems (not being detected).
I managed to have the HDD detected only by specifying at the boot prompt the option
After this, the HDD was visible, its partitions were visible and I could operate on it normally.