After upgrading Gtk to 2.4.0, from 2.2.0, gtk can't find the theme engine libs any more. This produces lots of these error messages: (gcalctool:8873): Gtk-WARNING **: Unable to locate theme engine in module_path: "pixmap", It does also mean that most themes don't work. I fixed it by symlinking /usr/lib/gtk-2.0/2.2.0/engines to .../2.4.0/engines, e.g: # cd /usr/lib/gtk-2.0/2.4.0; ln -s ../2.2.0/engines Reproducible: Always Steps to Reproduce: Upgrade from gtk-2.2.0 to gtk-2.4.0 through emerging.
If you un-symlink them, does revdep-rebuild (app-portage/gentoolkit) want to remerge the theme engines?
read the postinst note of the gtk+ ebuild.