[LAU] IRQ tuning

Hi, After some days browsing for info, it looks like I'm being unable to tune my IRQs to get my sound card on its own, exclusive IRQ. I'm using 2.6.21.3-rt9 on Debian Etch now, but: a) sound card is on IRQ 17 with ehci on IRQ 17 too. Both sound card (intel hda) and usb are motherboard (NVIDIA CK 804) ones. I'm not getting xruns, and I was thinking it was quite fine and probably hardware-related. b) However, I can not get those nice 255 IRQ vectors even if local apic and io-apic on uniprocessor are active. I even tried to use debian kernel configuration as much as possible (on 2.6.18 I get the vectors) but they seem to be unavailable as soon as I patch the kernel with Ingo's patch. So I think now this could be software-related and I would be able to set IRQs. What's the matter? Could you guys give me some up-to-date pointers? Thanks Roman