This might have to do with the way SATA and PATA are set up in your system. It happened to me too, until I set SATA mode to 'enhanced' instead of 'compatible'. It seems that in 'compatible' mode my SATA disk was obsouring the PATA drives, or some such.
Too bad that 'enhanced' mode made my system unable to run my previous installation of Mandrake 10.
Too bad, also, that a bit later, when installing grub, the installer insisted on writing to (hd0), which does not exist at all in my system (the SATA hard disk is 'sda'). This is a reported bug, so it might me fixed soon; meanwhile, the computer freezes at that stage.
I tried to skip Grub and go with lilo, which sort of worked: lilo was indeed installed in the proper drive (wiping the previous lilo), and installation proceeded a bit further until it stalled again.
I tried installing in my portable, however, and everything went fine. It is a very nice system (though it CAN get better). I will keep on using it, for now.