Error ID 5 (source ACPI) on each start up

[Peter]

I get the following 2 errors in the event-protocol
(system) on each start up: (translated from German)
1) Source: ACPI, Category: none, Type: error, ID: 5
Description:
AMLI: ACPI-BIOS is attempting to WRITE to a invalid I/O
port-address (0X70) that is part of a protected address-
area (0X70 - 0X71). This can lead to system instability.
Contact your system manufacturer for tech. support...
2) Same source etc., ID: 4
Same description, except here ACPI-BIOS is attempting to
READ from a.m. invalid address.

I detected this only recently when my system (after 10
days of not using it) suddenly shuts down without any
warning or messages - as if someone is pulling the plug.
But according to the protocol it has been going on for
months....

Any ideas what's going on and how to solve??

Thanks very much