From the official Pidgin web site
To setup the PPA, follow these steps:
1. Click to download the Pidgin PPA package.
2. Select Open with: and GDebi Package Installer. Click OK.
3. Click Install Package.
4. Click Close. Then close GDebi.
After doing this, check for and apply updates:
1. Click System, point to Administration, and click Update Manager.
2. Click Check.
3. Click Install Updates.
That helped me, hope that will help you as well.
Give it a try.