Skype on Ubuntu 10.04 - mic doesn't work

I got the following fix from here, but it does not tell the entire story:
(my setup: Acer Aspire One AO751h, Ubuntu Lucid 10.04.2 LTS)

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I had the same problem on an Acer Timeline for a long time, but the balance trick works.


Solution:
A better way than changing the output balance is to use alsamixer or pavucontrol and mute one of the input channels. In alsamixer: F4 to change to recording, left/right to move to microphone, and z or c to mute one channel. In pavucontrol go to the "input devices" tab, unlock the channels, and mute one of the channels.


It seems the normal volume control uses one balance slider for all inputs and outputs together. 

The reality is that two poorly designed (and worse implemented) pieces of software interact in a way to make it virtually impossible for the average user to figure out what's going on:

• Pulse Audio -- it still amazes me how a simple problem (enable audio on a PC) could be made so complicated and unusable;
• Skype for Linux -- a real disgrace that a company of the might and power of Skype could let us down so badly: I just wish they had the decency of release the software open source, so we could fix it ourselves!

Be that as it may, in addition to the 'fix' above, you need to also disable the "Allow Skype to adjust mixer levels" in the Sound Options tab of Skype - otherwise you can see skype continually adjusting your microphone's gain down until it gets to the point of being unaudible.

Leaving it here for future reference: I don't expect Skype to fix this anytime soon!