I have had this problem for numerous version of banshee.

When (re)scanning the library with new content (ie adding music)
banshee just crashes right out.

I have tried a few times to catch it with --debug-sql
but whenever I try - It usually imports the whole library with no issues!

Until now!
Finally it crashed with a --debug-sql

*Note* I thought it might be a display/speed related gtk bug & not related to
sql, But the problem ONLY seems to occur when I'm ADDING to the library.
Just rescanning (Trying to make it trip up) never makes it crash. (Which IS good)
 
Here is the last entry (And also the attachment of the entire log).

[2 Debug 00:31:49.033] Executed in 0ms UPDATE CoreTracks SET Rating = 0,LastStreamError = 0,PrimarySourceID = 1,ArtistID = 1,AlbumID = 34,TagSetID = 0,MusicBrainzID = NULL,MimeType = 'taglib/mp3',FileSize = 7340160,FileModifiedStamp = 1245967250,LastSyncedStamp = 1295616709,Attributes = 5,Title = 'Aneiki - Superhero',TitleSort = NULL,MetadataHash = 'cd3967654e5be1f1893f95ea0a59b678',TrackNumber = 16,TrackCount = 0,Disc = 2,DiscCount = 0,Duration = 213708,Year = 2002,Genre = 'Pop',Composer = NULL,Conductor = NULL,Grouping = NULL,Copyright = NULL,LicenseUri = NULL,Comment = NULL,BPM = 0,BitRate = 275,SampleRate = 44100,BitsPerSample = 0,Score = 0,PlayCount = 0,SkipCount = 0,ExternalID = 0,LastPlayedStamp = NULL,LastSkippedStamp = NULL,DateAddedStamp = 1295068288,DateUpdatedStamp = 1295616709,Uri = 'file:///media/Core/Audio/mp3.Modern.Music/mp3.Compilations/2002.Pepsi%20Chart%20Hits%20Volume%205/Disc2/16.Aneiki%20-%20Superhero.mp3',TitleSortKey = X'0E020E700E210E320E360E32070207020E910E9F0E7E0E210E8A0E2C0E210E8A0E7C010101018023068200',TitleLowered = 'aneiki - superhero' WHERE TrackID = 793
System.NullReferenceException: Object reference not set to an instance of an object
  at Hyena.Widgets.RoundedFrame.DrawFrame (Cairo.Context cr, Rectangle clip) [0x00000] 
  at Hyena.Widgets.RoundedFrame.OnExposeEvent (Gdk.EventExpose evnt) [0x00000] 
  at Gtk.Widget.exposeevent_cb (IntPtr widget, IntPtr evnt) [0x00000] 
   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()
michael@msgpc:~$