time is too slow with ACPI enabled

Hello,

I am testing the current developer-kernel 2.5.50 on my AMD K6-III 450MHz on a ASUS P5A Mainboard with the Ali Aladdin V chipset.
I compiled in the ACPI support, and without the boot option 'acpi=off' the time is approximately 3-4 times too slow.
'top' refreshes too slowly, the ping times are too small and the seconds shown with 'date' pass too slow, too...
When ACPI is forced 'off' the time seems to be correctly...

My .config file is attached. For further information just contact me...

Thomas Schlichter