Originally Posted by mdmbkr
I've tried 2.6.22 amd64 smp with and without iommu=soft. I've also tried disabling the iommu and memhole mapping in the bios, to no effect. I've also tried using mem=1g and/or iommu=soft with 2.6.15 amd64 smp, to no effect.
Then you're suffering from a different problem. In each case the bug described here was solved by iommu=soft.