Steps to reproduce:
1. Launch banshee
2. Plug in your MTP device
3. Wait a little moment :)


Stack trace:
[bartek@AcerTux ~]$ banshee-1 --debug
** Running Mono with --debug   **

** (/usr/lib/banshee-1/Banshee.exe:3029): WARNING **: Symbol file /usr/lib/mono/gac/NDesk.DBus/1.0.0.0__f6716e4f9b2ed099/NDesk.DBus.dll.mdb has incorrect version (expected 50.0, got 39)
[Info  17:03:25.439] Running Banshee 1.3.3

** (/usr/lib/banshee-1/Banshee.exe:3029): WARNING **: Symbol file /usr/lib/mono/gac/Mono.Addins/0.3.0.0__0738eb9f132ed756/Mono.Addins.dll.mdb has incorrect version (expected 50.0, got 39)

** (Banshee:3029): WARNING **: Symbol file /usr/lib/mono/gac/NDesk.DBus.GLib/1.0.0.0__f6716e4f9b2ed099/NDesk.DBus.GLib.dll.mdb has incorrect version (expected 50.0, got 39)
[Debug 17:03:27.623] Bus.Session.RequestName ('org.bansheeproject.Banshee') replied with PrimaryOwner
[Debug 17:03:27.637] Core service started (DBusServiceManager, 0,002643s)
[Debug 17:03:27.642] Registering remote object /org/bansheeproject/Banshee/DBusCommandService (Banshee.ServiceStack.DBusCommandService) on org.bansheeproject.Banshee
[Debug 17:03:27.661] Core service started (DBusCommandService, 0,022386s)
[Debug 17:03:27.930] Opened SQLite connection to /home/bartek/.config/banshee-1/banshee.db
[Debug 17:03:27.931] Core service started (DbConnection, 0,267633s)
[Debug 17:03:27.947] Database version 22 is up to date
[Debug 17:03:28.014] Core service started (PreferenceService, 0,064259s)
[Debug 17:03:28.015] Registering remote object /org/bansheeproject/Banshee/SourceManager (Banshee.Sources.SourceManager) on org.bansheeproject.Banshee
[Debug 17:03:28.015] Core service started (SourceManager, 0,001447s)
[Debug 17:03:28.501] Core service started (MediaProfileManager, 0,485421s)
[Debug 17:03:28.503] Registering remote object /org/bansheeproject/Banshee/PlayerEngine (Banshee.MediaEngine.PlayerEngineService) on org.bansheeproject.Banshee
[Debug 17:03:28.506] Core service started (PlayerEngine, 0,004827s)
[Debug 17:03:28.521] Configuration client extension loaded (Banshee.GnomeBackend.GConfConfigurationClient)
[Debug 17:03:28.696] IO provider extension loaded (Banshee.IO.Unix.Provider)
[Debug 17:03:28.756] Core service started (TranscoderService, 0,064414s)
[Debug 17:03:28.761] Registering remote object /org/bansheeproject/Banshee/PlaybackController (Banshee.PlaybackController.PlaybackControllerService) on org.bansheeproject.Banshee
[Debug 17:03:28.762] Core service started (PlaybackController, 0,004541s)
[Debug 17:03:28.764] Core service started (ImportSourceManager, 0,000925s)
[Debug 17:03:28.773] Core service started (LibraryImportManager, 0,009392s)
[Debug 17:03:28.774] Core service started (UserJobManager, 0,000666s)
[Debug 17:03:28.800] Core service started (HardwareManager, 0,025688s)
[Debug 17:03:28.805] Bus.Session.RequestName ('org.bansheeproject.CollectionIndexer') replied with PrimaryOwner
[Debug 17:03:28.809] Registering remote object /org/bansheeproject/Banshee/CollectionIndexerService (Banshee.Collection.Indexer.CollectionIndexerService) on org.bansheeproject.CollectionIndexer
[Debug 17:03:28.811] Core service started (CollectionIndexerService, 0,01048s)
[Debug 17:03:28.878] Adding icon theme search path: /usr/share/banshee-1/icons
[Debug 17:03:28.880] Core service started (GtkElementsService, 0,06807s)
[Debug 17:03:29.000] Core service started (InterfaceActionService, 0,120148s)
[Debug 17:03:29.004] Album artwork path set to /home/bartek/.cache/album-art
[Debug 17:03:29.004] Core service started (ArtworkManager, 0,003786s)

** (Banshee:3029): WARNING **: Symbol file /usr/lib/mono/gac/taglib-sharp/2.0.3.0__db62eba44689b5b0/taglib-sharp.dll.mdb has incorrect version (expected 50.0, got 39)

** (Banshee:3029): WARNING **: Symbol file /usr/lib/mono/gac/Mono.Addins.Setup/0.3.0.0__0738eb9f132ed756/Mono.Addins.Setup.dll.mdb has incorrect version (expected 50.0, got 39)

** (Banshee:3029): WARNING **: Symbol file /usr/lib/mono/gac/Mono.Addins.Gui/0.3.0.0__0738eb9f132ed756/Mono.Addins.Gui.dll.mdb has incorrect version (expected 50.0, got 39)
[Debug 17:03:31.016] Registering remote object /org/bansheeproject/Banshee/ClientWindow (Nereid.PlayerInterface) on org.bansheeproject.Banshee
[Debug 17:03:31.016] Core service started (NereidPlayerInterface, 2,01152s)
[Debug 17:03:31.034] Using GNOME 2.22 API for Multimedia Keys
[Debug 17:03:31.035] Extension service started (MultimediaKeysService, 0,017103s)
[Debug 17:03:31.037] Extension service started (DapService, 0,001617s)

** (Banshee:3029): WARNING **: Symbol file /usr/lib/mono/gac/Boo.Lang.Compiler/2.0.0.0__32c39770e9a21a67/Boo.Lang.Compiler.dll.mdb has incorrect version (expected 50.0, got 39)
[Debug 17:03:31.091] Extension service started (BooScriptService, 0,053636s)
[Debug 17:03:31.155] Extension service started (AudioCdService, 0,064168s)
[Debug 17:03:31.176] Extension service started (BookmarksService, 0,019942s)
[Debug 17:03:32.062] GStreamer pipeline does not run: audioconvert ! xingenc bitrate=128 ! id3v2mux
[Debug 17:03:32.315] GStreamer pipeline does not run: audioconvert ! fluwmaenc bitrate=64000 vbr=false ! fluasfmux
[Debug 17:03:32.316] Extension service started (GStreamerCoreService, 1,13979s)
[Debug 17:03:32.331] (libbanshee:player) Using built-in equalizer element
[Debug 17:03:32.364] Player state change: NotReady -> Ready
[Debug 17:03:32.402] Enabling equalizer preset: Drumm 'n' Bass
[Debug 17:03:32.427] Player state change: Ready -> Idle
[Debug 17:03:32.436] (libbanshee:player) Disabled ReplayGain
[Debug 17:03:32.453] Extension service started (GnomeService, 0,016766s)

** (Banshee:3029): WARNING **: Symbol file /usr/lib/mono/gac/Boo.Lang/2.0.0.0__32c39770e9a21a67/Boo.Lang.dll.mdb has incorrect version (expected 50.0, got 39)
[Debug 17:03:32.773] Extension service started (NotificationAreaService, 0,319678s)
[Debug 17:03:33.211] Extension service started (PodcastService, 0,437063s)
[Debug 17:03:33.246] Extension service started (LastfmRecommendationService, 0,034661s)
[Debug 17:03:33.284] Core service started (Network, 0,006364s)
[Debug 17:03:33.285] Audioscrobbler state: connected
[Debug 17:03:33.289] Extension service started (AudioscrobblerService, 0,042761s)
[Debug 17:03:33.292] Extension service started (CoverArtService, 0,002763s)
[Info  17:03:33.298] All services are started 5,669236s
[Debug 17:03:34.040] Registering remote object /org/bansheeproject/Banshee/SourceManager/PlayQueue (Banshee.PlayQueue.PlayQueueSource) on org.bansheeproject.Banshee
[Debug 17:03:34.178] Loaded IScreensaverManager: Banshee.GnomeBackend.GnomeScreensaverManager
[Debug 17:03:34.976] Creating Pango.Layout, configuring Cairo.Context
[Debug 17:03:35.036] Creating Pango.Layout, configuring Cairo.Context
[Debug 17:03:35.134] Creating new surface cache for 9216 KB (max) images, capped at 1 MB (113 items)
[Debug 17:03:35.152] Creating Pango.Layout, configuring Cairo.Context
[Info  17:03:35.510] nereid Client Started
[Debug 17:03:35.515] Delayed Initializating Banshee.Podcasting.PodcastService
[Debug 17:03:35.529] Refreshing any podcasts that haven't been updated in over an hour
[Debug 17:03:35.550] Delayed Initializating Banshee.Dap.DapService
[Debug 17:03:35.557] Dap support extension loaded: Banshee.Dap.Mtp
PTP: Opening session
[Debug 17:04:07.019] Found DAP support (Banshee.Dap.Mtp.MtpSource) for device My Zen
Stacktrace:

  at (wrapper managed-to-native) System.Object.__icall_wrapper_mono_string_new_wrapper (intptr) <0x00004>
  at (wrapper managed-to-native) System.Object.__icall_wrapper_mono_string_new_wrapper (intptr) <0xffffffff>
  at (wrapper unknown) Mtp.PlaylistStruct.PtrToStructure (intptr,object) <0xffffffff>
  at (wrapper runtime-invoke) Mtp.MtpDeviceStruct.runtime_invoke_void_intptr_object (object,intptr,intptr,intptr) <0xffffffff>
  at (wrapper managed-to-native) System.Runtime.InteropServices.Marshal.PtrToStructure (intptr,System.Type) <0x00004>
  at (wrapper managed-to-native) System.Runtime.InteropServices.Marshal.PtrToStructure (intptr,System.Type) <0xffffffff>
  at Mtp.MtpDevice.GetPlaylists () [0x00017] in /home/bartek/rpmbuild/BUILD/banshee-1-1.3.3/src/Libraries/Mtp/Mtp/MtpDevice.cs:194
  at Banshee.Dap.Mtp.MtpSource.LoadFromDevice () [0x000cb] in /home/bartek/rpmbuild/BUILD/banshee-1-1.3.3/src/Dap/Banshee.Dap.Mtp/Banshee.Dap.Mtp/MtpSource.cs:181
  at Banshee.Dap.DapSource.ThreadedLoadDeviceContents (object) [0x00022] in /home/bartek/rpmbuild/BUILD/banshee-1-1.3.3/src/Dap/Banshee.Dap/Banshee.Dap/DapSource.cs:278
  at (wrapper runtime-invoke) System.Object.runtime_invoke_void__this___object (object,intptr,intptr,intptr) <0xffffffff>

Native stacktrace:

	/usr/lib/libmono.so.0 [0x181502]
	/usr/lib/libmono.so.0 [0x1a1fb3]
	[0x11040c]
	/lib/libc.so.6(strlen+0xb) [0x76743b]
	/usr/lib/libmono.so.0(mono_string_new+0x2c) [0x1da1fc]
	/usr/lib/libmono.so.0(mono_string_new_wrapper+0x33) [0x1da2a3]
	[0x5857cda]
	[0x1c11466]
	[0x1128f83]
	/usr/lib/libmono.so.0 [0x1582b2]
	/usr/lib/libmono.so.0(mono_runtime_invoke+0x73) [0x1d7a43]
	/usr/lib/libmono.so.0 [0x209406]
	[0x6650a0d]
	[0x1c111c3]
	[0x75e6226]
	[0x75e5c7a]
	[0x5b9021e]
	/usr/lib/libmono.so.0 [0x1582b2]
	/usr/lib/libmono.so.0(mono_runtime_invoke+0x73) [0x1d7a43]
	/usr/lib/libmono.so.0(mono_runtime_invoke_array+0x3ac) [0x1dc8cc]
	/usr/lib/libmono.so.0 [0x1dcb1a]
	/usr/lib/libmono.so.0 [0x21fc9f]
	/usr/lib/libmono.so.0 [0x220130]
	/usr/lib/libmono.so.0 [0x21c42f]
	/usr/lib/libmono.so.0 [0x293936]
	/usr/lib/libmono.so.0 [0x2b7875]
	/lib/libpthread.so.0 [0x89e51f]
	/lib/libc.so.6(clone+0x5e) [0x7d402e]

Debug info from gdb:

warning: the debug information found in "/usr/lib/debug//usr/lib/libmtp.so.8.1.0.debug" does not match "/usr/lib/libmtp.so.8" (CRC mismatch).

warning: the debug information found in "/usr/lib/debug/usr/lib/libmtp.so.8.1.0.debug" does not match "/usr/lib/libmtp.so.8" (CRC mismatch).

0x00110416 in __kernel_vsyscall ()

=================================================================
Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries 
used by your application.
=================================================================


Other information:
Banshee launched under Fedora 10. System is fully updated. Mono version 2.0.1.