On a clean 32-bit 12.04 machine if you attempt to install Skype the following workflow occurs.
1) You see a app detail page with a "enable source" button where the install button would be
2) Click "enable source"
3) Type the root password and some background processing starts
4) return to skype install and there is a not found shown
5) wait for background task spinner to complete updating the database
6) Skype now shows up
On a clean 32-bit 12.04 machine if you attempt to install Skype the following workflow occurs.
1) You see a app detail page with a "enable source" button where the install button would be
2) Click "enable source"
3) Type the root password and some background processing starts
4) return to skype install and there is a not found shown
5) wait for background task spinner to complete updating the database
6) Skype now shows up