When enabling a11y "Screen Keyboard" in gnome shell there is a lot of Gtk-Message: Failed to load module "caribou-gtk-module" in ".xsession-errors". Installing caribou-gtk3-module seems to fix that issue ... but I do not know if it makes any real difference. The description of caribou-gtk*-module packages is not very helpful in explaining their role. caribou-0.4.4.2-6.fc18.x86_64 caribou-gtk3-module-0.4.4.2-6.fc18.x86_64
The caribou-gtk*-module packages were added to the gnome-desktop comps for f18 and f19 so default installations should work. It's debatable if there should be an rpm requires.
I guess there is no harm in having Requires:caribou-gtk2-module Requires:caribou-gtk3-module in main caribou package. I will build the update in F18 then.
caribou-0.4.4.2-7.fc18 has been submitted as an update for Fedora 18. https://admin.fedoraproject.org/updates/caribou-0.4.4.2-7.fc18
Package caribou-0.4.4.2-7.fc18: * should fix your issue, * was pushed to the Fedora 18 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing caribou-0.4.4.2-7.fc18' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2012-20663/caribou-0.4.4.2-7.fc18 then log in and leave karma (feedback).
caribou-0.4.4.2-7.fc18 has been pushed to the Fedora 18 stable repository. If problems still persist, please make note of it in this bug report.