This is a simple step by step walkthrough to install Pidgin 2.4.0. I do not take any responsibility for any damages to your computers or anything else.

Step 1: Uninstall pidgin: sudo apt-get remove pidgin
Step 2: Download and install in this order,
Step 2a:pidgin-data,
Step 2b:libpurple0,
Step 2c: pidgin
Step 3: Your done!