I hope this will help others with the 9.04 sound problem.
Running a new install of Linux Mint Gloria. All the hardware worked out of the box except sound.
I got sound working on an Intel Corporation 82801I chip on hp dv3-2157cl laptop with these 3 steps
1. Install as usual, and do all the updates and package manager upgrades to kernel 22.214.171.124
2. Install Alsa 1.0.20 from this forum:http://monespaceperso.org/blog-en/2009/05/09/upgrade-alsa-1020-on-ubuntu-jaunty-904/
3. Open a terminal and edit alsa-base.conf as follows:
sudo gedit /etc/modprobe.d/alsa-base.conf
When the file is open add the following lines to the end of the file after "options snd-pcsp index=-2"
alias snd-card-0 snd-hda-intel
alias sound-slot-0 snd-hda-intel
options snd-hda-intel model=dell-m4-1 enable_msi=1
Save/close and reboot