When rescanning the music library, Banshee occasionally crashes.  It did not do this when running banshee-1 --debug --redirect-log and it only sometimes crashes when running from an application launcher.  I've attached the output when I just ran banshee-1 from the terminal when it did crash.  Let me know what further information you need and I'll try to provide it.

:~$ banshee-1
[Info  08:20:13.662] Running Banshee 1.9.0: [Debian GNU/Linux unstable (sid) (linux-gnu, x86_64) @ 2010-11-16 19:31:28 UTC]
[Info  08:20:14.602] Updating web proxy from GConf
[Info  08:20:14.713] All services are started 0.869491
[Info  08:20:15.675] nereid Client Started
Exception in Gtk# callback delegate
  Note: Applications can use GLib.ExceptionManager.UnhandledException to handle the exception.
System.NullReferenceException: Object reference not set to an instance of an object
  at Hyena.Widgets.RoundedFrame.DrawFrame (Cairo.Context cr, Rectangle clip) [0x00000] in <filename unknown>:0 
  at Hyena.Widgets.RoundedFrame.OnExposeEvent (Gdk.EventExpose evnt) [0x00000] in <filename unknown>:0 
  at Gtk.Widget.exposeevent_cb (IntPtr widget, IntPtr evnt) [0x00000] in <filename unknown>:0 
   at GLib.ExceptionManager.RaiseUnhandledException(System.Exception e, Boolean is_terminal)
   at Gtk.Widget.exposeevent_cb(IntPtr widget, IntPtr evnt)
   at Gtk.Application.gtk_main()
   at Gtk.Application.Run()
   at Banshee.Gui.GtkBaseClient.Run()
   at Banshee.Gui.GtkBaseClient.Startup()
   at Hyena.Gui.CleanRoomStartup.Startup(Hyena.Gui.StartupInvocationHandler startup)
   at Banshee.Gui.GtkBaseClient.Startup()
   at Banshee.Gui.GtkBaseClient.Startup(System.String[] args)
   at Nereid.Client.Main(System.String[] args)
   at System.AppDomain.ExecuteAssembly(System.Reflection.Assembly , System.String[] )
   at System.AppDomain.ExecuteAssemblyInternal(System.Reflection.Assembly a, System.String[] args)
   at System.AppDomain.ExecuteAssembly(System.String assemblyFile, System.Security.Policy.Evidence assemblySecurity, System.String[] args)
   at System.AppDomain.ExecuteAssembly(System.String assemblyFile)
   at Booter.Booter.BootClient(System.String clientName)
   at Booter.Booter.Main()