muine crashes if music files are changened on runtime

How to reproduce this bug:

1. Start Muine.
2. Start EasyTag
3. Change with EasyTag some tags and filenames, which are observed by muine.
4. Save them all at one time.
5. Muine won't react anymore and crashes after a while

If you save just a single file muine don't have problems.

Lookup failed for /home/prometoys/media/audio/music/Chaoze One/Chaoze One - Koppstoff EP/01_chaoze_one_-_ppstoff-mein_bloc-hbz.mp3
Lookup failed for /home/prometoys/media/audio/music/Chaoze One/Chaoze One - Koppstoff EP/01_chaoze_one_-_ppstoff-mein_bloc-hbz.mp3.IklGfu

Unhandled Exception: System.Exception: Failed to load metadata: Unknown format
at Muine.Metadata..ctor (string) <0x000b0>
at Muine.SongDatabase.SyncSong (Muine.Song) <0x00070>
at Muine.PlaylistWindow.GetSingleSong (string,bool) <0x000a0>
at Muine.PlaylistWindow.AddSong (string) <0x00020>
at Muine.InotifyPlugin.OnNotify () <0x00470>
at (wrapper delegate-invoke) System.MulticastDelegate.invoke_void () <0x0006c>
at Gtk.ThreadNotify.CallbackWrapper () <0x00094>
at (wrapper delegate-invoke) System.MulticastDelegate.invoke_bool () <0x00074>
at IdleProxy.Handler () <0x00060>
at (wrapper native-to-managed) IdleProxy.Handler () <0x00050>
in (unmanaged) 0xfefcdb8
at (wrapper managed-to-native) Gtk.Application.gtk_main () <0x00080>
at Gtk.Application.Run () <0x0000c>
at Muine.Global.Main (string[]) <0x00618>

Package: muine
Version: 0.8.5-1ubuntu3
Severity: wishlist

-- System Information:
Debian Release: testing/unstable
  APT prefers edgy-updates
  APT policy: (990, 'edgy-updates'), (990, 'edgy-security'), (990, 'edgy-proposed'), (990, 'edgy-backports'), (990, 'edgy')
Architecture: powerpc (ppc)
Shell: /bin/sh linked to /bin/dash
Kernel: Linux 2.6.17-9-powerpc
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8)

Versions of packages muine depends on:
ii gconf2 2.14.0-1ubuntu2 GNOME configuration database syste
ii gstreamer0.10 0.10.10-1ubuntu1 GStreamer plugin for GnomeVFS
ii gstreamer0.10 0.10.10-1ubuntu1 GStreamer plugins from the "base"
ii libatk1.0-0 1.12.1-0ubuntu1 The ATK accessibility toolkit
ii libc6 2.4-1ubuntu10 GNU C Library: Shared libraries
ii libcairo2 1.2.4-1ubuntu1 The Cairo 2D vector graphics libra
ii libdbus-1-cil 0.63.git.20060719-2ubuntu1 CLI binding for D-BUS interprocess
ii libflac7 1.1.2-5ubuntu1 Free Lossless Audio Codec - runtim
ii libfontconfig 2.3.2-7ubuntu2 generic font configuration library
ii libgconf2-4 2.14.0-1ubuntu2 GNOME configuration database syste
ii libgconf2.0-c 2.16.0-0ubuntu1 CLI binding for GConf 2.16
ii libgdbm3 1.8.3-3 GNU dbm database routines (runtime
ii libglade2.0-c 2.10.0-0ubuntu1 CLI binding for the Glade librarie
ii libglib2.0-0 2.12.3-1ubuntu1 The GLib library of C routines
ii libglib2.0-ci 2.10.0-0ubuntu1 CLI binding for the GLib utility l
ii libgnome2.0-c 2.16.0-0ubuntu1 CLI binding for Gnome 2.16
ii libgnomevfs2- 2.16.0-0ubuntu3 GNOME virtual file-system (runtime
ii libgstreamer0 0.10.10-1ubuntu1 Core GStreamer libraries and eleme
ii libgtk2.0-0 2.10.3-0ubuntu1 The GTK+ graphical user interface
ii libgtk2.0-cil 2.10.0-0ubuntu1 CLI binding for the GTK+ toolkit 2
ii libid3tag0 0.15.1b-8 ID3 tag reading library from the M
ii libmono-corli 1.1.17.1-1ubuntu5 Mono core library (1.0)
ii libmono-syste 1.1.17.1-1ubuntu5 Mono System.Web library
ii libmono-syste 1.1.17.1-1ubuntu5 Mono System libraries (1.0)
ii libmono1.0-ci 1.1.17.1-1ubuntu5 Mono libraries (1.0)
ii libogg0 1.1.3-2ubuntu1 Ogg Bitstream Library
ii liborbit2 1:2.14.3-0ubuntu1 libraries for ORBit2 - a CORBA ORB
ii libpango1.0-0 1.14.4-0ubuntu1 Layout and rendering of internatio
ii libvorbis0a 1.1.2-1ubuntu1 The Vorbis General Audio Compressi
ii libvorbisfile 1.1.2-1ubuntu1 The Vorbis General Audio Compressi
ii libx11-6 2:1.0.3-0ubuntu3 X11 client-side library
ii libxcursor1 1.1.7-0ubuntu1 X cursor management library
ii libxext6 2:1.0.1-1ubuntu1 X11 miscellaneous extension librar
ii libxfixes3 1:4.0.1-0ubuntu1 X11 miscellaneous 'fixes' extensio
ii libxi6 2:1.0.1-0ubuntu1 X11 Input extension library
ii libxinerama1 2:1.0.1-4build1 X11 Xinerama extension library
ii libxml2 2.6.26.dfsg-2ubuntu3 GNOME XML library
ii libxrandr2 2:1.1.1-0ubuntu1 X11 RandR extension library
ii libxrender1 1:0.9.1-0ubuntu1 X Rendering Extension client libra
ii mono-runtime 1.1.17.1-1ubuntu5 Mono runtime
ii zlib1g 1:1.2.3-13ubuntu1 compression library - runtime

muine recommends no packages.

-- no debconf information