[audio] Why pcm audio signal can't be read back through pcm channel?

[Yuri]

I noticed that I can't record sound that comes from pcm channel. For 
example audacity only records my voice coming from mic, but doesn't 
record other person's voice that skype sends into pcm channel.
This used to work before. I look at mixer -- all channels are open.

Why pcm doesn't get sent back? Is there something wrong with mixer?

snd_es137x.ko is used:
pcm0: <AudioPCI ES1370> port 0xec00-0xec3f irq 17 at device 1.0 on pci8
pcm0: es1370_wrcodec: timed out
pcm0: es1370_wrcodec: timed out
pcm0: es1370_wrcodec: timed out
pcm0: [ITHREAD]
pcm0: <Playback: DAC1,DAC2 / Record: ADC>

Yuri