I encountered this crash in Tomboy, immediately after checking the preference Hilight Wikiwords. I was able to set it subsequently so it's either intermittent or just random that I had done that prior to the crash.
This traceback may help isolate it, as I happened to have run it from a shell. Sorry, I don't have the -dbg package installed.
jim@hobbes:~$ tomboy -icon &
[INFO 11:20:08.790] Initializing Mono.Addins
(Tomboy:3754): Gtk-CRITICAL **: IA__gtk_text_tag_table_remove: assertion `tag->table == table' failed
[ERROR 11:25:54.678] Error cleaning up addin after sync: Object reference not set to an instance of an object
at Tomboy.Sync.SyncManager.SynchronizationThread () [0x00000] in <filename unknown>:0
[WARN 11:26:13.223] Getting configuration from the GNOME keyring failed with the following message: The keyring daemon is not available
Marshaling toggled signal
Exception in Gtk# callback delegate
Note: Applications can use GLib.ExceptionManager.UnhandledException to handle the exception.
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> GLib.GException: Configuration server couldn't be contacted: D-BUS error: Method "Set" with signature "s(ib)" on interface "org.gnome.GConf.Database" doesn't exist
at GConf.Client.SetValue (System.String key, GConf.Value val) [0x00000] in <filename unknown>:0
at GConf.ClientBase.Set (System.String key, System.Object val) [0x00000] in <filename unknown>:0
at GConf.PropertyEditors.PropertyEditor.Set (System.Object val) [0x00000] in <filename unknown>:0
at GConf.PropertyEditors.PropertyEditorBool.Set (System.Object val) [0x00000] in <filename unknown>:0
at GConf.PropertyEditors.PropertyEditorToggleButton.Toggled (System.Object obj, System.EventArgs args) [0x00000] in <filename unknown>:0
at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (System.Reflection.MonoMethod,object,object[],System.Exception&)
at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
--- End of inner exception stack trace ---
at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
at System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) [0x00000] in <filename unknown>:0
at System.Delegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in <filename unknown>:0
at System.MulticastDelegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in <filename unknown>:0
at System.Delegate.DynamicInvoke (System.Object[] args) [0x00000] in <filename unknown>:0
at GLib.Signal.ClosureInvokedCB (System.Object o, GLib.ClosureInvokedArgs args) [0x00000] in <filename unknown>:0
at GLib.SignalClosure.Invoke (GLib.ClosureInvokedArgs args) [0x00000] in <filename unknown>:0
at GLib.SignalClosure.MarshalCallback (IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data) [0x00000] in <filename unknown>:0
at GLib.ExceptionManager.RaiseUnhandledException(System.Exception e, Boolean is_terminal)
at GLib.SignalClosure.MarshalCallback(IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data)
at Gtk.Application.gtk_main()
at Gtk.Application.Run()
at Tomboy.GnomeApplication.StartMainLoop()
at Tomboy.Application.StartMainLoop()
at Tomboy.Tomboy.StartTrayIcon()
at Tomboy.Tomboy.Main(System.String[] args)
tomboy -help
ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: tomboy 1.8.0-1ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 1.23-0ubuntu3
Architecture: amd64
Date: Sat Oct 22 11:33:37 2011
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
ProcEnviron:
PATH=(custom, no user)
LANG=en_US.UTF-8
SHELL=/bin/bash
SourcePackage: tomboy
UpgradeStatus: Upgraded to oneiric on 2011-10-15 (7 days ago)