Strange mdadm errors after upgrade

[Gawain Lynch]

Right after "Setting hostname" I am getting this:

  mdadm: no arrays found in config file
  Missing major number for persistent device.
  Couldn't create ioctl argument.
  last_lba(): I don't know how to handle files with mode 41ed
  read error, sector 0
  read error, sector 1
  read error, sector 29
  Missing major number for persistent device.
  Couldn't create ioctl argument.

However /dev/md0 comes online and the volume group on it also gets
initialised.  Where is does become an issue (I'm not sure if it is
related but it all happened after the upgrade) is that I keep getting
the following in the logs (followed by a hang):

Nov  2 01:08:37 gandalf kernel: irq 19: nobody cared (try booting with
the "irqpoll" option)
Nov  2 01:08:37 gandalf kernel:  [<c040571a>] dump_trace+0x69/0x1af
Nov  2 01:08:37 gandalf kernel:  [<c0405878>] show_trace_log_lvl
+0x18/0x2c
Nov  2 01:08:37 gandalf kernel:  [<c0405e18>] show_trace+0xf/0x11
Nov  2 01:08:37 gandalf kernel:  [<c0405e47>] dump_stack+0x15/0x17
Nov  2 01:08:37 gandalf kernel:  [<c044245e>] __report_bad_irq+0x36/0x7d
Nov  2 01:08:37 gandalf kernel:  [<c044264b>] note_interrupt+0x1a6/0x1e3
Nov  2 01:08:37 gandalf kernel:  [<c0441cca>] __do_IRQ+0xba/0xf2
Nov  2 01:08:37 gandalf kernel:  [<c0406ca8>] do_IRQ+0x9e/0xbc
Nov  2 01:08:37 gandalf kernel:  =======================
Nov  2 01:08:37 gandalf kernel: handlers:
Nov  2 01:08:37 gandalf kernel: [<c057a001>] (usb_hcd_irq+0x0/0x50)
Nov  2 01:08:37 gandalf kernel: Disabling IRQ #19
Nov  2 01:10:07 gandalf kernel: hda: dma_timer_expiry: dma status ==
0x64
Nov  2 01:12:37 gandalf kernel: hdg: dma_timer_expiry: dma status ==
0x64
Nov  2 01:15:37 gandalf kernel: hda: DMA interrupt recovery
Nov  2 01:18:07 gandalf kernel: hda: lost interrupt
Nov  2 01:21:37 gandalf kernel: PDC202XX: Secondary channel reset.
Nov  2 01:24:37 gandalf kernel: hdg: DMA interrupt recovery
Nov  2 01:27:07 gandalf kernel: hdg: lost interrupt
Nov  2 01:29:37 gandalf kernel: hda: dma_timer_expiry: dma status ==
0x64
Nov  2 01:32:37 gandalf kernel: hdh: dma_timer_expiry: dma status ==
0x64
Nov  2 01:35:37 gandalf kernel: hda: DMA interrupt recovery
Nov  2 01:38:07 gandalf kernel: hda: lost interrupt

As a side note, I am using software RAID, not the Promise fake raid, but
the disks are on the Promise controller.

Ideas?

Take care,

Gawain