Well - when knotify isn't hammering your CPU (under Gnome) - (having killed &
re-started it), when I stopped it again I got the appended trace.

Looks like gtk+ should be more circumspect as to it's xsettings handling. I got
a similar crash changing the font size (from the panel notification area) as
well FWIW.

Backtrace was generated from '/opt/gnome/bin/gnome-terminal'

0xffffe410 in __kernel_vsyscall ()
#0  0xffffe410 in __kernel_vsyscall ()
#1  0x40eea40b in __waitpid_nocancel () from /lib/tls/libpthread.so.0
#2  0x4009a4d5 in libgnomeui_module_info_get ()
   from /opt/gnome/lib/libgnomeui-2.so.0
#3  <signal handler called>
#4  0x40e96a7d in g_type_check_instance_is_a ()
   from /opt/gnome/lib/libgobject-2.0.so.0
#5  0x4062cf55 in gtk_widget_get_toplevel ()
   from /opt/gnome/lib/libgtk-x11-2.0.so.0
#6  0x40522376 in gtk_propagate_event ()
   from /opt/gnome/lib/libgtk-x11-2.0.so.0
#7  0x405224af in gtk_main_do_event () from /opt/gnome/lib/libgtk-x11-2.0.so.0
#8  0x4074c03a in gdk_screen_get_setting ()
   from /opt/gnome/lib/libgdk-x11-2.0.so.0
#9  0x40f196dc in g_main_context_dispatch ()
   from /opt/gnome/lib/libglib-2.0.so.0
#10 0x40f1cb4b in g_main_context_check () from /opt/gnome/lib/libglib-2.0.so.0
#11 0x40f1ce67 in g_main_loop_run () from /opt/gnome/lib/libglib-2.0.so.0
#12 0x40523191 in gtk_main () from /opt/gnome/lib/libgtk-x11-2.0.so.0
#13 0x080617b6 in main ()

Thread 2 (Thread 1099004848 (LWP 15222)):
#0  0xffffe410 in __kernel_vsyscall ()
No symbol table info available.
#1  0x40ee93db in __read_nocancel () from /lib/tls/libpthread.so.0
No symbol table info available.
#2  0x40f1b80e in g_timeout_add () from /opt/gnome/lib/libglib-2.0.so.0
No symbol table info available.
#3  0x40f37e81 in g_static_private_free () from /opt/gnome/lib/libglib-2.0.so.0
No symbol table info available.
#4  0x40ee4277 in start_thread () from /lib/tls/libpthread.so.0
No symbol table info available.
#5  0x410370ce in clone () from /lib/tls/libc.so.6
No symbol table info available.
#6  0x41817bb0 in ?? ()
No symbol table info available.

Thread 1 (Thread 1091276960 (LWP 15190)):
#0  0xffffe410 in __kernel_vsyscall ()
No symbol table info available.
#1  0x40eea40b in __waitpid_nocancel () from /lib/tls/libpthread.so.0
No symbol table info available.
#2  0x4009a4d5 in libgnomeui_module_info_get ()
   from /opt/gnome/lib/libgnomeui-2.so.0
No symbol table info available.
#3  <signal handler called>
No symbol table info available.
#4  0x40e96a7d in g_type_check_instance_is_a ()
   from /opt/gnome/lib/libgobject-2.0.so.0
No symbol table info available.
#5  0x4062cf55 in gtk_widget_get_toplevel ()
   from /opt/gnome/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#6  0x40522376 in gtk_propagate_event ()
   from /opt/gnome/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#7  0x405224af in gtk_main_do_event () from /opt/gnome/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#8  0x4074c03a in gdk_screen_get_setting ()
   from /opt/gnome/lib/libgdk-x11-2.0.so.0
No symbol table info available.
#9  0x40f196dc in g_main_context_dispatch ()
   from /opt/gnome/lib/libglib-2.0.so.0
No symbol table info available.
#10 0x40f1cb4b in g_main_context_check () from /opt/gnome/lib/libglib-2.0.so.0
No symbol table info available.
#11 0x40f1ce67 in g_main_loop_run () from /opt/gnome/lib/libglib-2.0.so.0
No symbol table info available.
#12 0x40523191 in gtk_main () from /opt/gnome/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#13 0x080617b6 in main ()
No symbol table info available.
#0  0xffffe410 in __kernel_vsyscall ()