Sorry about the dramatic summary above, but I don't know how else to describe it. The problem seems to be a combination of inadequate software and inadequate documentation.
A while back I installed dapper on a slightly old computer (a pentium 3 box of some sort) and found that the sound cards would be loaded in random order. I read stuff on the web about putting index=0 somewhere and index=1 somewhere else, but I never got the hang of it and in the end I simply set index=-2 for the internal sound card so that at least something would work.
More recently I installed dapper on a pentium 4 box and then upgraded it to edgy. But I got the same problem. Unfortunately I need both sound cards to work on this machine. I have tried editing /etc/modprobe.d/alsa-base in various ways and now have no sound cards working. I am not sure if I ever had more than one sound card working at a time on this machine since Ubuntu has been installed. Which card that would be appeared to be randomly determined at boot time.
One thing that really puzzles me is that the installer-created /etc/modprobe.d/alsa-base configured an emu10k1 card (which I do have - an Audigy2 to be precise) and a via something or other, which I definitely don't have (I have an ICH5 motherboard with an intel8x0 chip). As far as I remember this was the same setup it left me with on the older computer. In that case I had assumed this to be correct the machine really did have an emu10k1 device (some kind of soundblaster card) while I didn't know what kind of sound chip was on the motherboard and therefore assumed that the installer's selection of the via driver had been correct.
In the past, in other Linux distributions, I would use alsaconf to sort this kind of thing out and it never let me down. The removal of alsaconf from Ubuntu (and presumably from debian as well) has created a much bigger problem than it solves.
To summarise:
1. The installer incorrectly identifies one of the sound cards. Perhaps it doesn't identify them at all and creates a standard alsa-base file regardless?
2. Out of the box, the sound cards seem to load in random order.
3. There are no tools to fix this.
4. There appear to be no instructions readily available to enable even experienced computer users to fix the configuration files themselves.
What SHOULD happen is that configuration of sound cards should be AT LEAST as easy as in Windows. A user should never even have to think about such issues as which driver is going to load first at boot time.
There is a confusing typo above:
"In that case I had assumed this to be correct the machine really did have an emu10k1 device..."
should read
"In that case I had assumed this to be correct because the machine really did have an emu10k1 device..."