So.. I have to make a premise: I realized after a hour of testing.. that asus GSDX was not working. So no DS3D and no EAX meanwhile (even though I'm not sure of the actual EAX support)
Anyway, just to answer your question, my .ini file didn't reverted back. It's even true I had no Generic Hardware back then...
but perhaps, did you try to assign to DeviceName.. your actual sound card name?
The setting could be case sensitive.. so be sure to check it with ALCapsViewer or in windows device manager.
And you should also take note that the game is not using latest OpenAL libraries.
So replacing those in the .\Binaries folder with the updated ones (or just delete OpenAL32.dll and wrap_oal.dll if you already have latest version in windows folder) may help.
As side note.. did you experienced mouse smoothing? Bacause even though I mentioned it as present (it was enabled in the .ini file after all) I couldn't actually feel a difference between true and false options...
All this was tested with the demo avaibale on steam. I count to report back when I'll have re-tested audio accuracy. (Miles sound using both openAL and DS seem too messy even for it btw)
Regards
EDIT: stupid miles have little mention whatsoever of OpenAL