Skype useless in 11.04 no microphone

I have been trying to follow the advice in various Ubuntu threads suggesting work-arounds for the problem of getting the
internal microphone of a Dell laptop (Studio 1558) to function with Skype, a program which although not part of the Ubuntu project, is nevertheless quite useful to me. When I updated recently to Ubuntu 11.04 the problem appeared, whereas under
Ubuntu 10.04 and 10.10 Skype compatibility and functionality was fine. I have tried manipulating the Sound Preferences dialog parameters, as well as invoking alsamixer (gnome and terminal versions) and Pulse Audio Volume Control, setting one channel
of the i nternal mike to 0% and the other to 100%, but so far without positive result on my ability to hear my own voice when I make a Skype test call (everything else, including video) seems to be working fine. There is, of course the "work-around" to use
the chat facility of Skype to exchange brief comments, but, obviously it's better if my call partners can hear my voice, especially
since I can hear them. I am wondering if the problem is related to compatibility with Banshee. In any case all suggestions would be appreciated.

I am indebted to Tao Huang who (via Launchpad) provided the following fix for the internal mike problem with Skype under
Ubuntu 11.4:
       Following thesestebs to enable your internal microphone:
             1. Start alsamixer in a terminal
             2. Hit "tab" or "F4" to switch to capture configuration
             3. Hit right arrow key 3 times to select "<Input Source>"
            4. Hit Up/Down arrow key several times to select "Input Source [Internal Mic 1]" as your current input source.

as Tao Huang states this is just a temporary solution and you will have to do this again once you reboot your machine.

This solved the same issue for me:
http://ubuntuforums.org/showpost.php?p=10382638&postcount=5

The only solution to make microphone work is to install linux-backports-modules-alsa-generic...

Just go to:

Menu / System / Administration / Synaptic Package Manager

And search and mark for installation:

linux-backports-modules-alsa-generic

tip: if you have multiple versions click on the first and read the description which should inform what name to install...

If after the reboot and mic mute is off, still does not work, just go to terminal and type:

sudo nano /etc/modprobe.d/alsa-base.conf

and add or change the following:

options snd-hda-intel model=auto enable=yes

Then Ctrl+X, type Y to write and exit, reboot and mic will work.

Bye and have lots of fun with Ubuntu (the best).