Sorry this last one is without. dmesg output without 'noapic pci=usepirqmask' applied to /boot/grub/menu.lst: #cat /var/log/dmesg >ACPI: PCI Interrupt Link [LNKH] (IRQs 3 4 5 7 10 11 14 15) *0, disabled. usbcore: registered new driver usbfs usbcore: registered new driver hub PCI: Using ACPI for IRQ routing IOAPIC[0]: Set PCI routing entry (1-16 -> 0xa9 -> IRQ 16 Mode:1 Active:1) ACPI: PCI interrupt 0000:00:07.0[A] -> GSI 16 (level, low) -> IRQ 16 IOAPIC[0]: Set PCI routing entry (1-17 -> 0xb1 -> IRQ 17 Mode:1 Active:1) ACPI: PCI interrupt 0000:00:0a.0[A] -> GSI 17 (level, low) -> IRQ 17 ACPI: PCI interrupt 0000:00:0c.0[A] -> GSI 17 (level, low) -> IRQ 17 IOAPIC[0]: Set PCI routing entry (1-18 -> 0xb9 -> IRQ 18 Mode:1 Active:1) ACPI: PCI interrupt 0000:00:0d.0[A] -> GSI 18 (level, low) -> IRQ 18 IOAPIC[0]: Set PCI routing entry (1-19 -> 0xc1 -> IRQ 19 Mode:1 Active:1) ACPI: PCI interrupt 0000:00:0e.0[A] -> GSI 19 (level, low) -> IRQ 19 ACPI: PCI interrupt 0000:00:0e.1[A] -> GSI 19 (level, low) -> IRQ 19 IOAPIC[0]: Set PCI routing entry (1-20 -> 0xc9 -> IRQ 20 Mode:1 Active:1) ACPI: PCI interrupt 0000:00:0f.0[B] -> GSI 20 (level, low) -> IRQ 20 ACPI: PCI interrupt 0000:00:0f.1[A] -> GSI 20 (level, low) -> IRQ 20 IOAPIC[0]: Set PCI routing entry (1-21 -> 0xd1 -> IRQ 21 Mode:1 Active:1) ACPI: PCI interrupt 0000:00:10.0[A] -> GSI 21 (level, low) -> IRQ 21 ACPI: PCI interrupt 0000:00:10.1[A] -> GSI 21 (level, low) -> IRQ 21 ACPI: PCI interrupt 0000:00:10.2[B] -> GSI 21 (level, low) -> IRQ 21 ACPI: PCI interrupt 0000:00:10.3[B] -> GSI 21 (level, low) -> IRQ 21 ACPI: PCI interrupt 0000:00:10.4[C] -> GSI 21 (level, low) -> IRQ 21 IOAPIC[0]: Set PCI routing entry (1-22 -> 0xd9 -> IRQ 22 Mode:1 Active:1) ACPI: PCI interrupt 0000:00:11.5[C] -> GSI 22 (level, low) -> IRQ 22 ACPI: PCI interrupt 0000:01:00.0[A] -> GSI 16 (level, low) -> IRQ 16 number of MP IRQ sources: 15. number of IO-APIC #1 registers: 24. testing the IO APIC....................... IO APIC #1...... .... register #00: 01000000 ....... : physical APIC id: 01 .... register #01: 00178003 ....... : max redirection entries: 0017 ....... : PRQ implemented: 1 ....... : IO APIC version: 0003 .... IRQ redirection table: NR Log Phy Mask Trig IRR Pol Stat Dest Deli Vect: 00 000 00 1 0 0 0 0 0 0 00 01 001 01 0 0 0 0 0 1 1 39 02 001 01 0 0 0 0 0 1 1 31 03 001 01 0 0 0 0 0 1 1 41 04 001 01 0 0 0 0 0 1 1 49 05 001 01 0 0 0 0 0 1 1 51 06 001 01 0 0 0 0 0 1 1 59 07 001 01 0 0 0 0 0 1 1 61 08 001 01 0 0 0 0 0 1 1 69 09 001 01 0 1 0 1 0 1 1 71 0a 001 01 0 0 0 0 0 1 1 79 0b 001 01 0 0 0 0 0 1 1 81 0c 001 01 0 0 0 0 0 1 1 89 0d 001 01 0 0 0 0 0 1 1 91 0e 001 01 0 0 0 0 0 1 1 99 0f 001 01 0 0 0 0 0 1 1 A1 10 001 01 1 1 0 1 0 1 1 A9 11 001 01 1 1 0 1 0 1 1 B1 12 001 01 1 1 0 1 0 1 1 B9 13 001 01 1 1 0 1 0 1 1 C1 14 001 01 1 1 0 1 0 1 1 C9 15 001 01 1 1 0 1 0 1 1 D1 16 001 01 1 1 0 1 0 1 1 D9 17 000 00 1 0 0 0 0 0 0 00 IRQ to pin mappings: IRQ0 -> 0:2 IRQ1 -> 0:1 IRQ3 -> 0:3 IRQ4 -> 0:4 IRQ5 -> 0:5 IRQ6 -> 0:6 IRQ7 -> 0:7 IRQ8 -> 0:8 IRQ9 -> 0:9 IRQ10 -> 0:10 IRQ11 -> 0:11 IRQ12 -> 0:12 IRQ13 -> 0:13 IRQ14 -> 0:14 IRQ15 -> 0:15 IRQ16 -> 0:16 IRQ17 -> 0:17 IRQ18 -> 0:18 IRQ19 -> 0:19 IRQ20 -> 0:20 IRQ21 -> 0:21 IRQ22 -> 0:22 .................................... done. agpgart: Detected AGP bridge 0 agpgart: Maximum main memory to use for agp memory: 941M agpgart: AGP aperture is 64M @ 0xf8000000 PCI-DMA: Disabling IOMMU. IA32 emulation $Id: sys_ia32.c,v 1.32 2002/03/24 13:02:28 ak Exp $ VFS: Disk quotas dquot_6.5.1 Dquot-cache hash table entries: 512 (order 0, 4096 bytes) devfs: 2004-01-31 Richard Gooch (