I'm using the Faenza icon set in 10.04LTS. Within the gnome-panel, alt-tab and possible more instances Firefox does not use the Faenza icons. All other apps seem too, just not Firefox.
Any idea why, or how to fix it?
Not a direct fix, but it might still be acceptable:
https://addons.mozilla.org/de/firefox/addon/gtk-native/
A Firefox theme which applies your gtk theme. I think that it changes the icons too
How did you install the Faenza icons ? When I installed them from this ppa it works :
https://launchpad.net/~tiheum/+archive/equinox
sudo add-apt-repository ppa:tiheum/equinox
sudo apt-get update
sudo apt-get install faenza-icon-theme