Benjamin A. Okopnik wrote:
The frequency of how often this happens varies: sometimes, it's every single boot until I remove the laptop battery; at other times, it's only about one boot out of every five. It seems to be related to IRQ problems (booting the laptop without its battery, and inserting it after the boot, results in the problem nearly disappearing - it only happens in ~1 of every 20 boots.)
I think you are excluding an hardware problem because on the same machine you also run Windows (or something else) and it sounds good, right?
The sporadic nature of the problem seems suspicious, in particular because your machine has a very common (and tested) chipset. As you can see on http://www.linux-on-laptops.com/acer.html, people using your laptop seems to have audio that just works.
I have a Sony laptop with a i855 chipset that works too. Have you tried to upgrade your Acer BIOS?And, do the problem comes indifferently (and with similar probability) after a reboot or a complete poweroff? Have you tryed with some linux live CD (Ubuntu, Knoppix) to see if something behaves differently? But i suspect it is not a kernel/distibution problem... Have you contacted the Acer support or visited their website to see if there are some broken model or some known problem?
Good luck. Cesare.