I am running Ubuntu 12.04 and compiled and installed GTK 3.4 to go through some GTK developer tutorials.

Installing this version of GTK has caused problems with Unity.

All system dialogs and top bar now have a different (older) look, and when I try to launch Nautilus I get the following message:

Gtk-Message: Failed to load module "canberra-gtk-module" 
Initializing nautilus-open-terminal extension 
Initializing nautilus-dropbox 1.4.0 
Initializing nautilus-gdu extension 
nautilus: symbol lookup error: nautilus: undefined symbol: ubuntu_menu_proxy_get

I have run make uninstall on the newer version of GTK and reinstalled just about every package I can think of, but I am still having the same problem.

How can I repair the default Ubuntu GTK libraries?

EDIT

Also, I noticed that my desktop icons are gone (launcher works), and I can't interact with the desktop. I can't drag any shortcuts to it, etc.