Comment 2 for bug 672398

I can also produce the problem (Pinta 0.5 on Ubuntu 10.10).
The following error is displayed:

System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NullReferenceException: Object reference not set to an instance of an object
  at Pinta.Tools.TextTool.DrawText (Cairo.ImageSurface dst, System.String textFont, System.String text, Point pt, Size measuredSize, Boolean antiAliasing, Cairo.ImageSurface brush8x8) [0x00000] in <filename unknown>:0
  at Pinta.Tools.TextTool.DrawText (Cairo.ImageSurface dst, System.String textFont, System.String text, Point pt, Size measuredSize, Boolean antiAliasing, Color color) [0x00000] in <filename unknown>:0
  at Pinta.Tools.TextTool.RenderText (Cairo.ImageSurface surf, Int32 lineNumber) [0x00000] in <filename unknown>:0
  at Pinta.Tools.TextTool.RedrawText (Boolean cursorOn) [0x00000] in <filename unknown>:0
  at Pinta.Tools.TextTool.OnKeyPress (Gtk.DrawingArea canvas, Gtk.KeyPressEventArgs args) [0x00000] in <filename unknown>:0
  at Pinta.Tools.TextTool.OnKeyDown (Gtk.DrawingArea canvas, Gtk.KeyPressEventArgs args) [0x00000] in <filename unknown>:0
  at Pinta.Core.BaseTool.DoKeyPress (Gtk.DrawingArea canvas, Gtk.KeyPressEventArgs args) [0x00000] in <filename unknown>:0
  at Pinta.Gui.Widgets.PintaCanvas.PintaCanvas_KeyPressEvent (System.Object o, Gtk.KeyPressEventArgs e) [0x00000] in <filename unknown>:0
  at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (object,object[],System.Exception&)
  at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
  --- End of inner exception stack trace ---
  at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
  at System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) [0x00000] in <filename unknown>:0
  at System.Delegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in <filename unknown>:0
  at System.MulticastDelegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in <filename unknown>:0
  at System.Delegate.DynamicInvoke (System.Object[] args) [0x00000] in <filename unknown>:0
  at GLib.Signal.ClosureInvokedCB (System.Object o, GLib.ClosureInvokedArgs args) [0x00000] in <filename unknown>:0
  at GLib.SignalClosure.Invoke (GLib.ClosureInvokedArgs args) [0x00000] in <filename unknown>:0
  at GLib.SignalClosure.MarshalCallback (IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data) [0x00000] in <filename unknown>:0