i was having serious stutter issues after i had installed a radeon 9500pro into my system and also moved my pvr 250 over one slot on my MB.
it turned out to be 2 things: damned acpi and its love of grouping components on a single irq and the fact that my motherboard automatically shares pci slot 3 with usb controller 2 and agp slot with usb controller 1 (irq's 24 and 16 respectively in acpi land)
after considering long and hard if i should disable acpi and set my computer to standard pc i decided against it as the stupid irq's would still have been shared by the motherboard anyway.
instead i opted to disable usb controller #1 and #2 and then shift my only usb device (a wireless 802.11g device) to usb #3. reinstalled my drivers for the device, checked to see the irq share (conflict) no longer existed and then headed for the powerdvd setup screen.
enabled dxva and hit play.....low and behold i have stutter free sound!!!!!!
i guess the moral is that if you are having serious stutter in applications other than sage (especially if you have no stutter with dxva disabled) then check your irq groupings in the device manager first.
interestingly (and annoyingly) enough i didn't have this problem with my older radeon 7000 card installed but i really didn't want to downgrade my card again just to fix the problem.
as a side note i still get the no audio problem on sage startup but i'm pretty sure that is the 2133 drivers causing that (and occasional stutter also) so i'll be deleting those and replacing with the ones from the hauppauge site tonight.
nick.