At least some OldWorld machines use this IDE-controler.
As a work around, I've provided this as a module, you can download it at: http://dev.gentoo.org/~josejx/cmd64x.ko.bz2 Let me know if you use it / have any problems.
CONFIG_BLK_DEV_CMD64X is included as a module (and in the initramfs) on the upcoming LiveCD.