ACPI error in Event Log

Hi,

On Vostro 3450 with switchable graphics, I get this message in Event Viewer:

ACPI: ACPI BIOS is attempting to write to an illegal PCI Operation Region (0xf8100068), Please contact your system vendor for technical assistance.

This message appears when I switch from Power-Saving GPU to High-Performance GPU in Catalyst Control Center.

I am using the driver from Dell website (version 8.840) and BIOS version A13.

Any suggestions?