Most recent kernel where this bug did not occur:
Distribution: Gentoo
Hardware Environment: ASUS a8v deluxe
Software Environment:
Problem Description:

I running 2.6.12-gentoo-r10
I have a ASUS a8v motherboard with a AMD64 X2

This gives me problem with clock drift
(see http://bugzilla.kernel.org/show_bug.cgi?id=5105)

So I tried using notsc to force usage of pm timer.

But!
The the acpi code find the fadt->xpm_tmr_blk.address to 0
Making the code yet again fall back to PIT/TSC

I booted my system and run
perch> grep PM_ /proc/ioports 
0808-080b : PM_TMR

And harded the address 0x808 into pmtmr_ioport
This works. The system is using pmtmr and I get no clock drift
(tested now for ~a day)

But why do ACPI find 0 as pmtmr_ioport?