You're in luck(?) Last week I didn't even know the "pci" utilities existed, but I've been doing some modem research of my own.
You don't usually WANT to override the IRQ for a PCI bus device. One of the primary reasons we WENT to PCI was to escape the IRQ/DMA/address conflicts. PCI IRQ's are sharable, unlike the old ATA IRQ's.
Actually, having the IRQ show up as "0" makes me wonder if the device in fact has IRQ capabilities at all. Winmodems are notorious for their dependency on the CPU, and it's possible that this device is polled rather than interrupt driven.
