Hey all. When I installed 8.04 on my 3,1 macbook pro and then installed pommed, I had some really strange volume problems including bad adjustment, non-audible ranges and "popping". Here's how I fixed them:
Open volume control, then make sure your selected device is HDA intel.
Right click on the volume icon on your bar and select preferences. Set your selection to "Master".
Go to System>Preferences>Sound and set your device to PCM.
Open a terminal:
Go to the audio section and set the step value = 3. Make sure your mixer element for volume adjustment is "PCM". Save and close.sudo gedit /etc/pommed.conf
Reinstall pommedsudo apt-get remove pommed
Log out and back in.sudo apt-get install pommed
The reinstallation of pommed starts using the new conf file. Not sure what the deal is there. After I did this, i was able to adjust the volume correctly. In the volume controls, I set "Master" to a little below full, PCM is adjusted by you, and Front all the way to full. Sorry if any of this is confusing. I'm getting back into the swing of ubuntu information, it might take me a bit.