Firewire interface -> dropouts, IRQ?

X-Post & f'up to rec.audio.tech

Hi all,

I am using the audio firewire interfaces Yamaha 01X and i88X. If I make
the 01X the wordclock master, I have serious dropouts. If my PC is the
master, I have a short dropout roughly every 3-4 minutes.

I have read that audio dropouts can occur, if the firewire interface has
the same IRQ as other devices, which can easily happen with modern
machines (APCI). And indeed, my onboard firewire adaptor has the same
IRQ as the video card, and they are not changeable in windows (checkbox
greyed out).

Is there a way to change the IRQ on the mobo?
If not, would it help if I buy a new firewire adaptor? Does it make
sense to get a PCI-E firewire thingy, since that bus does not use IRQ?

My system:
ASUS P5K
Intel Core Duo E6500
NVIDIA 8600 GT
Windows XP 64bit

Thanks for any help

Boris