Comment 31 for bug 274424

Karmic Alpha3 64bit solved this for me.

The livecd installer, and the first boot into the newly installed desktop, had the customary stuttering and repeating, but an update of all pending packages + a reboot and the login sound was perfect.

All subsequent sounds are fine also. This is on a HP Pavilion dv4 Notebook PC

:~$ sudo lshw -C multimedia
  *-multimedia
       description: Audio device
       product: 82801I (ICH9 Family) HD Audio Controller
       vendor: Intel Corporation
       physical id: 1b
       bus info: pci@0000:00:1b.0
       version: 03
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list
       configuration: driver=HDA Intel latency=0
       resources: irq:22 memory:df300000-df303fff

:~$ uname -a
Linux aetna 2.6.31-5-generic #24-Ubuntu SMP Sat Aug 1 12:47:58 UTC 2009 x86_64 GNU/Linux