valgrind log, the error happens after killing syncdaemon (which was mentioned in the description of one of the dups):

"==18403== Invalid read of size 4
==18403==    at 0x4208656: g_object_unref (gobject.c:2916)
==18403==    by 0x411D9EE: g_desktop_app_info_finalize (gdesktopappinfo.c:189)
==18403==    by 0x4208827: g_object_unref (gobject.c:3024)
==18403==    by 0x80510BD: app_menu_item_dispose (app-menu-item.c:102)
==18403==    by 0x4208797: g_object_unref (gobject.c:2987)
==18403==    by 0x407AB81: dbusmenu_menuitem_dispose (menuitem.c:351)
==18403==    by 0x4208797: g_object_unref (gobject.c:2987)
==18403==    by 0x407F10D: prop_array_teardown (server.c:949)
==18403==    by 0x4081592: menuitem_property_idle (server.c:1111)
==18403==    by 0x428AF0F: g_idle_dispatch (gmain.c:5205)
==18403==    by 0x428E3B2: g_main_context_dispatch (gmain.c:3054)
==18403==    by 0x428E74F: g_main_context_iterate.isra.21 (gmain.c:3701)
==18403==    by 0x428EC2A: g_main_loop_run (gmain.c:3895)
==18403==    by 0x437C934: (below main) (libc-start.c:260)
==18403==  Address 0x670fc40 is 0 bytes inside a block of size 20 free'd
==18403==    at 0x402B1CC: free (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==18403==    by 0x42945BA: standard_free (gmem.c:98)
==18403==    by 0x429472F: g_free (gmem.c:252)
==18403==    by 0x42AAEDA: g_slice_free1 (gslice.c:1111)
==18403==    by 0x4225EBD: g_type_free_instance (gtype.c:1957)
==18403==    by 0x420882F: g_object_unref (gobject.c:3037)
==18403==    by 0x805170B: app_menu_item_new (app-menu-item.c:344)
==18403==    by 0x8052354: on_sync_menu_app_exists (sync-service.c:508)
==18403==    by 0x4153115: emit_signal_instance_in_idle_cb (gdbusconnection.c:3715)
==18403==    by 0x428AF0F: g_idle_dispatch (gmain.c:5205)
==18403==    by 0x428E3B2: g_main_context_dispatch (gmain.c:3054)
==18403==    by 0x428E74F: g_main_context_iterate.isra.21 (gmain.c:3701)
==18403==    by 0x428EC2A: g_main_loop_run (gmain.c:3895)
==18403==    by 0x437C934: (below main) (libc-start.c:260)
==18403== 
==18403== Invalid read of size 4
==18403==    at 0x4226E0A: g_type_check_instance_is_a (gtype.c:3989)
==18403==    by 0x4208670: g_object_unref (gobject.c:2916)
==18403==    by 0x411D9EE: g_desktop_app_info_finalize (gdesktopappinfo.c:189)
==18403==    by 0x4208827: g_object_unref (gobject.c:3024)
==18403==    by 0x80510BD: app_menu_item_dispose (app-menu-item.c:102)
==18403==    by 0x4208797: g_object_unref (gobject.c:2987)
==18403==    by 0x407AB81: dbusmenu_menuitem_dispose (menuitem.c:351)
==18403==    by 0x4208797: g_object_unref (gobject.c:2987)
==18403==    by 0x407F10D: prop_array_teardown (server.c:949)
==18403==    by 0x4081592: menuitem_property_idle (server.c:1111)
==18403==    by 0x428AF0F: g_idle_dispatch (gmain.c:5205)
==18403==    by 0x428E3B2: g_main_context_dispatch (gmain.c:3054)
==18403==    by 0x428E74F: g_main_context_iterate.isra.21 (gmain.c:3701)
==18403==    by 0x428EC2A: g_main_loop_run (gmain.c:3895)
==18403==    by 0x437C934: (below main) (libc-start.c:260)
==18403==  Address 0x670fc40 is 0 bytes inside a block of size 20 free'd
==18403==    at 0x402B1CC: free (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==18403==    by 0x42945BA: standard_free (gmem.c:98)
==18403==    by 0x429472F: g_free (gmem.c:252)
==18403==    by 0x42AAEDA: g_slice_free1 (gslice.c:1111)
==18403==    by 0x4225EBD: g_type_free_instance (gtype.c:1957)
==18403==    by 0x420882F: g_object_unref (gobject.c:3037)
==18403==    by 0x805170B: app_menu_item_new (app-menu-item.c:344)
==18403==    by 0x8052354: on_sync_menu_app_exists (sync-service.c:508)
==18403==    by 0x4153115: emit_signal_instance_in_idle_cb (gdbusconnection.c:3715)
==18403==    by 0x428AF0F: g_idle_dispatch (gmain.c:5205)
==18403==    by 0x428E3B2: g_main_context_dispatch (gmain.c:3054)
==18403==    by 0x428E74F: g_main_context_iterate.isra.21 (gmain.c:3701)
==18403==    by 0x428EC2A: g_main_loop_run (gmain.c:3895)
==18403==    by 0x437C934: (below main) (libc-start.c:260)"