Hi Benoit, This line in your dmesg:
> pciide1: using irq 15 for native-PCI interrupt is highly suspicious, especially since your machine also has pciide0. Can you send me dmesg for the following cases too: GENERIC with acpi enabled GENERIC.MP GENERIC.MP with acpi enabled and the output of # acpidump -o M2N-MX The latter produces several files; please create a tar file that contains them and send me that. Hopefully this will help me figuring out what goes wrong here. Thanks, Mark