problem of install 7.0 on notebook

[Zhang hw]

I have now could work on my notebook with freebsd 6.2-release and
6.3-prerelease, but there are still some problems such as acpi. So I
want to have a try of freebsd 7.0-beta-1.5, but I can't install it,
the boot process stop at pci probing:
pcib2:<PCI-PCI brige> at device 4.0 on pci0
pci16:<PCI-PCI bus> on pcib2
if acpi enable, it maybe show as:
pcib2:<ACPI PCI-PCI brige>...
pci16:<ACPI...
my cpu is athlon 64x2, I've tried both amd64 and i386 versions.
Help!