Hey Thomas, Just a heads up, Clark noted that on LS21s if the HPET is enabled in the BIOS, recent kernels hang at boot. I booted the current -git up after enabling HPET and sure enough: ENABLING IO-APIC IRQs ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1 ..MP-BIOS bug: 8254 timer not connected to IO-APIC ...trying to set up timer (IRQ0) through the 8259A ... ..... (found apic 0 pin 2) ... ....... failed. ...trying to set up timer as Virtual Wire IRQ... ..... failed. ...trying to set up timer as ExtINT IRQ... ..... failed :(. Kernel panic - not syncing: IO-APIC + timer doesn't work! Boot with apic=debug and send a report. Then try booting with the 'noapic' option. Full boot log attached. Disabling the HPET in the BIOS boots up fine. I then did some rough bisection to see when this showed up and apparently it hit sometime between 2.6.23 and 2.6.24-rc1. I'll do some further bisection on it next week, but if you have any quick ideas let me know. thanks -john