libgtk1.2 is not installed/installable, since it was removed from karmic 🙁
So i build a libglib1.2 & a libgtk1.2 32bits packages for karmic from source !
Get it here : http://gistlabs.homelinux.net/deb/libgtk+1.2-Karmic.tar.gz
Then install all the .deb files with : $sudo dpkg -i *.deb
Have Fun with it and read the rest of the post if you want to build it on another architecture.