Start Evolution with G_DEBUG=fatal_criticals, and Evolution will crash with message:

calendar-gui-CRITICAL **: file gnome-cal.c: line 2724: assertion `E_IS_SOURCE (source)' f ailed
aborting...


The trace is:
 ce709a25 waitid   (0, 1ae, 8046610, 3)
 ce6fd107 waitpid  (1ae, 8046724, 0) + 70
 d0380aee libgnomeui_segv_handle (6, 0, 80467d0) + aa
 ce7080df __sighndlr (6, 0, 80467d0, d0380a44) + f
 ce6fdc71 call_user_handler (6, 0, 80467d0) + 248
 ce6fddea sigacthandler (6, 0, 80467d0) + b3
 ce7095f5 _lwp_kill (1, 6) + 15
 ce6cdfdd raise    (6) + 22
 ce6b036f abort    (82b0078, cc1d3e70, ce7f0eb0, 1, cf68a2bc, cf6970f4) + 64
 ce7923e4 g_logv   (cc1d3e70, 8, cc1d3e80, 8046f10) + 32c
 ce792411 g_log    (cc1d3e70, 8, cc1d3e80, cc20c390, aa4, cc20c39c) + 29
 cc14eb9c gnome_calendar_add_source (832d990, 1, 0) + 10c
 cc0c4cad update_task_selection (829c840) + 11d
 cc0c72be create_component_view (816aaf0) + 4fe
 cc0c7561 impl_createView (816ab04, 81faf40, 80470e0) + 51
 d0f8b21e _ORBIT_skel_small_GNOME_Evolution_Component_createView (816ab04, 80470ac, 80470a8, 0, 80470e0, cc0c7510) + 3e
 cffb1c89 ORBit_c_stub_invoke (8195c98, d0fa7cac, 1, 80470ac, 80470a8, 0) + 171
 d0f8d9a3 GNOME_Evolution_Component_createView (8195c98, 81faf40, 80470e0) + 63
 0806faa2 init_view (81a45f0, 8289bf0) + 192
 0806fe5b switch_view (81a45f0, 8289bf0) + 6b
 080702ed sidebar_button_selected_callback (8275670, 2, 81a45f0) + 8d
 cf69e568 g_cclosure_marshal_VOID__INT (8281200, 0, 2, 80472fc, 804725c, 0) + 5c
 cf68a256 g_closure_invoke (8281200, 0, 2, 80472fc, 804725c) + 112
 cf69dba0 signal_emit_unlocked_R (8275640, 0, 8275670, 0, 80472fc) + 754
 cf69cea5 g_signal_emit_valist (8275670, c8, 0, 8047570) + 8cd
 cf69d041 g_signal_emit (8275670, c8, 0, 2) + 29
 080739d4 e_sidebar_select_button (8275670, 2) + 34
 08071978 e_shell_window_switch_to_component (81a45f0, 8291d88) + 158
 08071782 e_shell_window_new (81bedf0, 8291d88) + 262
 080681fd e_shell_create_window (81bedf0, 0, 0) + ad
 08075ae1 idle_cb  (0) + 1c1
 ce78cc57 g_idle_dispatch (8169f30, 8075920, 0) + 1f
 ce789ca4 g_main_dispatch (80b03d0) + 1c8
 ce78ad95 g_main_context_dispatch (80b03d0) + 85
 ce78b1b5 g_main_context_iterate (80b03d0, 1, 1, 80928a8) + 3d1
 ce78b7ba g_main_loop_run (81b8fb0) + 1ba
 d00bf462 bonobo_main (80479bc, 80478e4, d0ffb840, 8047830, 80478a0, 80998a0) + 5e
 0807621d main     (1, 8047928, 8047930) + 47d
 080624ea _start   (1, 8047a24, 0, 8047a4e, 8047a8c, 8047ace) + 7a


I will provide a patch soon.