Amithlon has a habit of puking on SATA devices/chipsets. My own Amithlon box will install and run for a bit on the onboard SATA on the mobo, then it packs it up and refuses to work.
It's an older machine, so I still have PATA/IDE onboard, the last of my machines to have an IDE port, sadly. IDE works 100% on said machine with Amithlon.
You running the latest kernel?
