The problem here is that pdaxrom use the dpms options via xset to suspend the Z and not apm,
in fact if you try apm --suspend, it exhibits the same behavior that pantau describe.
But as kapm is running, apm must be involved at some point.
I think we need to know what Sash has cook up with apm/ xset and get the sources of his hacks before we can try to implement something using the rtc.