Exception in Gtk# callback delegate when using standards compliant template

This is somewhat *similar* to bug# 460993 in where the exception gets reported, but I think just different enough to warrant a separate bug report. Hopefully this will help triangulate the exact causes of lat's instability. Because of this and the bug sighted lat is basically unusable. Which is too bad because *good* LDAP Gui Admin tools are darn hard to come by without shelling out some cash. All I did to crash lat was the following:

1. define a 'Domain User' template, consisting of the following LDAP Classes: top, person, organizationalPerson, inetOrgPerson.
2. navigate to the containing object for users, and attempt to create a new user record from that template.

> Le Pouffe < ... it crashes with this output:

lat [07483] INFO Starting lat (version 1.2.3)
Marshaling clicked signal
Exception in Gtk# callback delegate
  Note: Applications can use GLib.ExceptionManager.UnhandledException to handle the exception.
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
  at System.Collections.Generic.Dictionary`2[System.String,System.String].get_Item (System.String key) [0x00000] in <filename unknown>:0
  at lat.Template.GetAttributeDefaultValue (System.String attrName) [0x00000] in <filename unknown>:0
  at lat.CreateEntryDialog.insertValues (System.String[] values, System.String valueType) [0x00000] in <filename unknown>:0
  at lat.CreateEntryDialog.showAttributes () [0x00000] in <filename unknown>:0
  at lat.CreateEntryDialog..ctor (lat.Connection connection, lat.Template theTemplate) [0x00000] in <filename unknown>:0
  at lat.NewEntryDialog.OnOkClicked (System.Object o, System.EventArgs args) [0x00000] in <filename unknown>:0
  at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (System.Reflection.MonoMethod,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
   at GLib.ExceptionManager.RaiseUnhandledException(System.Exception e, Boolean is_terminal)
   at GLib.SignalClosure.MarshalCallback(IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data)
   at Gtk.Dialog.gtk_dialog_run(IntPtr )
   at Gtk.Dialog.Run()
   at lat.NewEntryDialog..ctor(lat.Connection connection, System.String dn)
   at lat.LdapTreeView.OnNewEntryActivate(System.Object o, System.EventArgs args)
   at System.Reflection.MonoMethod.InternalInvoke(System.Reflection.MonoMethod , System.Object , System.Object[] , System.Exception ByRef )
   at System.Reflection.MonoMethod.Invoke(System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
   at System.Reflection.MethodBase.Invoke(System.Object obj, System.Object[] parameters)
   at System.Delegate.DynamicInvokeImpl(System.Object[] args)
   at System.MulticastDelegate.DynamicInvokeImpl(System.Object[] args)
   at System.Delegate.DynamicInvoke(System.Object[] args)
   at GLib.Signal.ClosureInvokedCB(System.Object o, GLib.ClosureInvokedArgs args)
   at GLib.SignalClosure.Invoke(GLib.ClosureInvokedArgs args)
   at GLib.SignalClosure.MarshalCallback(IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data)
   at Gtk.Application.gtk_main()
   at Gtk.Application.Run()
   at Gnome.Program.Run()
   at LdapAdministrationTool.Main(System.String[] args)

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: lat 1.2.3-7.1
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic i686
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu3
Architecture: i386
Date: Fri Nov 4 18:09:37 2011
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111012)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_CA:en
 PATH=(custom, user)
 LANG=en_CA.UTF-8
 SHELL=/bin/bash
SourcePackage: lat
UpgradeStatus: No upgrade log present (probably fresh install)