On Fri, 30 Nov 2007, Manuel Bouyer wrote:
> I guess you're running a netbsd-4 kernel, right ? disable ACPI
> (both on Xen and the NetBSD kernel) or switch the IDE controller to
> AHCI mode in BIOS.

No, this was a current from day before yesterday.

NetBSD 4.99.38 (XEN3_DOM0) #8: Wed Nov 28 10:29:39 NZDT 2007

Turns out I'd put "noapic" as an argument to xen, based on something 
I'd read in some setup guide, when I'd been initially battling with 
getting grub going.  I've taken it out and all is fine with a nicely 
running domain0 - now to make some guest domains.

cheers
mark