ACPI problems afer update 6.3 to 7.0

[Eric SERVANT]

Hello everybody,

I have updated my system a few days ago from 6.3-STABLE to 7.0-STABLE.
With the system 6.3-STABLE all worked fine, but with 7.0 some problems
appear.

First : the percentage of processor states (user, nice, system, idle,
interrupt) are always 0.0%.
The display vmstat in the command systat display :

The alternate system clock has died!
Reverting to ``pigs'' display.

Second : reboot or shutdown doesn't work after the kernel messages (disk
synchronization, uptime). I must use the power button.

My computer : NEC Versa Note VX
BIOS Revision /126A2300 (04/03/2000)
acpi0: <NEC ND000018> on motherboard

Booting the kernel with boot_verbose, display this messages :
acpi: bad write to port 0x070 (8), val 0x52
acpi: bad read from port 0x071 (8)
These messages appear fourteen/fifteen times during the boot.

If someone have an idea... Thanks.

-- 
Eric S.