Make sure that you are using the Windows 8 RTM from Technet or the MSDN. Do not use the Windows 8 RC, RP, or CP, they are not the same thing; Windows 8 RTM is currently only available to Technet and MSDN subscribers.
ACPI is a configuration and power control interface. ACPI errors can be caused by a kernel-level driver bug, a bug in the system firmware, or a bug in an add-in OPROM such as that found in USB 3.0 controllers, storage controllers, VGA adapters, etc... Check for firmware updates for everything including add-in chips which are present on the motherboard.