Steps to reproduce:
1. Enable color management in F-spot preferences
2. Close F-spot
3. Try to open F-spot again


Stack trace:
chr1s@chris-desktop:/var/cache/pbuilder/intrepid-amd64/result$ f-spot --debug
** Running f-spot in Debug Mode **
** Running Mono with --debug   **
[Info  00:53:52.805] Initializing DBus
[Debug 00:53:53.134] DBusInitialization took 0.299736s
[Info  00:53:53.134] Initializing Mono.Addins
[Debug 00:53:53.638] Mono.Addins Initialization took 0.503021s
[Info  00:53:53.649] Starting new FSpot server

(f-spot:1262): Gtk-WARNING **: Theme directory scalable/animations/small/16x16 of theme oxygen has no size field


(f-spot:1262): Gtk-WARNING **: Theme directory scalable/animations/small/22x22 of theme oxygen has no size field

[Debug 00:53:54.023] Db Initialization took 0.224304s
[Debug 00:53:54.496] QueryToTemp took 0.115255s : SELECT id, time, uri, description, roll_id, default_version_id, rating, md5_sum FROM photos  WHERE id NOT IN (SELECT photo_id FROM photo_tags WHERE tag_id = 2) ORDER BY  time DESC
[Debug 00:53:54.753] Query took 0.032349s : SELECT * FROM photoquery_temp_0 LIMIT 100 OFFSET 0
[Debug 00:53:54.830] PhotosPerMonth took 0.052917s
[Debug 00:53:54.834] TimeAdaptor REAL Reload took 0.286251s
[Info  00:53:54.951] Starting BeagleService
[Debug 00:53:54.952] BeagleService startup took 1.8E-05s
[Info  00:53:54.952] Hack for gnome-settings-daemon engaged
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 TagSelectionWidget.IconDataFunc (Gtk.TreeViewColumn column, Gtk.CellRenderer renderer, TreeModel model, TreeIter iter) [0x00000] 
  at GtkSharp.TreeCellDataFuncWrapper.NativeCallback (IntPtr tree_column, IntPtr cell, IntPtr tree_model, IntPtr iter, IntPtr data) [0x00000] 
   at GLib.ExceptionManager.RaiseUnhandledException(System.Exception e, Boolean is_terminal)
   at GtkSharp.TreeCellDataFuncWrapper.NativeCallback(IntPtr tree_column, IntPtr cell, IntPtr tree_model, IntPtr iter, IntPtr data)
   at GtkSharp.TreeCellDataFuncWrapper.NativeCallback(IntPtr , IntPtr , IntPtr , IntPtr , IntPtr )
   at Gtk.Application.gtk_main()
   at Gtk.Application.gtk_main()
   at Gtk.Application.Run()
   at Gnome.Program.Run()
   at FSpot.Driver.Main(System.String[] args)


Other information: