Hi. Problem description:I had problems a few years ago with USB stopping when the screen saver kicked in, just a wild thought.
I have a problem with recording on HP nx6325 notebook (hda-intel with AD1981HD codec). Playback works fine, but after 5-10 min. of recording microphone stops working (playback works all the time). Unloading and loading sound modules fixes problem, but only for another 5-10 minutes. This problem exists from more than a year (at least from 2.6.17.13 kernel). In [1] we came to conclusion that this problem is ralated to IRQ sharing [2] (HDA Intel is on the same IRQ as sata_sil).
How to reproduce the problem:
1) on one console run arecord and see the output (You should see some garbage)
2) on another console run cat /etc/*
3) at once arecord on the first console gives no output
So, doing lot of hdd I/O occurs problem with mic.