Fedora 17, python 2.7.3
Call up Cinnamon settings, all options are fine, except if Themes is selected, then boom.
Output from command line run (N.B. -- the warning comes up when cinnamon-settings is started, the second (GLib-GIO-ERROR) is the one that occurs on crash when selecting Themes):
/usr/lib64/python2.7/site-packages/gobject/constants.py:24: Warning: g_boxed_type_register_static: assertion `g_type_from_name (name) == 0' failed
(cinnamon-settings.py:3221): GLib-GIO-ERROR **: Settings schema 'org.gnome.nautilus.preferences' does not contain a key named 'show-location-entry'
Cinnamon does not use org.gnome.nautilus.preferences, it should be looking in org.nemo.preferences. Check with your Fedora maintainer.
Fix in updates-testing