I can confirm the same issue with 2.6.22-1 too, now it is out.The ide-generic in /etc/initramfs-tools/modules trick also allows me to boot, but without DMA. My BIOS doesn't have any ide legacy, and is as up to date as possible (box is soon 3 years old).
It was working ok and doesn't anymore, so this is a regression : I don't think blaming the BIOS will help ;-)
What information could we give to help pinpoint what goes wrong?