Sitecore SIP active directory issues after authentication

I've setup the active directory LDAP module in Sitecore's Intranet Portal 3.2 product and have had limited success. I receive the error "Unable to cast object of type 'System.Configuration.SettingsPropertyValue' to type 'LightLDAP.ADSettingsPropertyValue'." when I click the "Ok" button on user properties, applying a user template with custom properties, when I try to view the workbox from the front end editor, and when I try to access any item in the content editor.

I am able to successfully sign-on through the LDAP module, manage CMS role access, security, etc. I am automatically logged in on the front-end, and can type in my domain\username\pwd and successfully authenticate though AD.

Any help would be much appreciated

Stack Trace

[InvalidCastException: Unable to cast object of type 'System.Configuration.SettingsPropertyValue' to type 'LightLDAP.ADSettingsPropertyValue'.]
   LightLDAP.SitecoreADProfileProvider.SetPropertyValues(SettingsContext context, SettingsPropertyValueCollection collection) +388
   Sitecore.Security.SwitchingProfileProvider.SetPropertyValues(SettingsContext context, SettingsPropertyValueCollection collection) +294
   System.Configuration.SettingsBase.SaveCore() +484
   System.Configuration.SettingsBase.Save() +72
   System.Web.Profile.ProfileBase.SaveWithAssert() +43
开发者_如何学编程   System.Web.Profile.ProfileBase.Save() +159
   Sitecore.Security.UserProfile.Save() +32
   Sitecore.Web.UI.HtmlControls.Registry.SetValue(String key, String value) +202
   Sitecore.Web.UI.HtmlControls.Listview.DoSetView(String name) +163
   Sitecore.Shell.Applications.ContentEditor.FileDropArea.OnLoad(EventArgs e) +693
   System.Web.UI.Control.LoadRecursive() +66
   System.Web.UI.Control.LoadRecursive() +191
   System.Web.UI.Control.AddedControl(Control control, Int32 index) +350
   Sitecore.Web.UI.Sheer.ClientPage.AddControl(Control parent, Control control, String placeholder) +240
   Sitecore.Shell.Applications.ContentEditor.EditorFormatter.AddEditorControl(Control parent, Control editor, Field field, Boolean hasRibbon, Boolean readOnly, String value) +249
   Sitecore.Shell.Applications.ContentEditor.EditorFormatter.RenderField(Control parent, Field field, Item fieldType, Boolean readOnly, String value) +1097
   Sitecore.Shell.Applications.ContentEditor.EditorFormatter.RenderField(Control parent, Field field, Item fieldType, Boolean readOnly) +204
   Sitecore.Shell.Applications.ContentEditor.Pipelines.RenderContentEditor.RenderSkinedContentEditor.RenderInput(Field field) +131
   Sitecore.Shell.Applications.ContentEditor.Pipelines.RenderContentEditor.RenderSkinedContentEditor.RenderElement(XmlNode element) +603
   Sitecore.Shell.Applications.ContentEditor.Pipelines.RenderContentEditor.RenderSkinedContentEditor.RenderChildElements(XmlNode element) +141
   Sitecore.Shell.Applications.ContentEditor.Pipelines.RenderContentEditor.RenderSkinedContentEditor.RenderMarker(XmlNode element) +175
   Sitecore.Shell.Applications.ContentEditor.Pipelines.RenderContentEditor.RenderSkinedContentEditor.RenderElement(XmlNode element) +674
   Sitecore.Shell.Applications.ContentEditor.Pipelines.RenderContentEditor.RenderSkinedContentEditor.RenderChildElements(XmlNode element) +141
   Sitecore.Shell.Applications.ContentEditor.Pipelines.RenderContentEditor.RenderSkinedContentEditor.RenderSectionPanel(XmlNode element) +270
   Sitecore.Shell.Applications.ContentEditor.Pipelines.RenderContentEditor.RenderSkinedContentEditor.RenderElement(XmlNode element) +635
   Sitecore.Shell.Applications.ContentEditor.Pipelines.RenderContentEditor.RenderSkinedContentEditor.AddText(XmlNode element) +494
   Sitecore.Shell.Applications.ContentEditor.Pipelines.RenderContentEditor.RenderSkinedContentEditor.RenderElement(XmlNode element) +717
   Sitecore.Shell.Applications.ContentEditor.Pipelines.RenderContentEditor.RenderSkinedContentEditor.AddText(XmlNode element) +494
   Sitecore.Shell.Applications.ContentEditor.Pipelines.RenderContentEditor.RenderSkinedContentEditor.RenderElement(XmlNode element) +717
   Sitecore.Shell.Applications.ContentEditor.Pipelines.RenderContentEditor.RenderSkinedContentEditor.Render(XmlDocument skin) +125
   Sitecore.Shell.Applications.ContentEditor.Pipelines.RenderContentEditor.RenderSkinedContentEditor.Process(RenderContentEditorArgs args) +353
   (Object , Object[] ) +79
   Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args) +240
   Sitecore.Shell.Applications.ContentManager.Editor.Render(RenderContentEditorArgs args, Control parent) +538
   Sitecore.Shell.Applications.ContentManager.ContentEditorForm.RenderEditor(Item item, Item root, Control parent, Boolean showEditor) +232
   Sitecore.Shell.Applications.ContentManager.ContentEditorForm.UpdateEditor(Item folder, Item root, Boolean showEditor) +345
   Sitecore.Shell.Applications.ContentManager.ContentEditorForm.Update() +344

[TargetInvocationException: Exception has been thrown by the target of an invocation.]
   System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) +0
   System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) +1255
   System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) +38
   Sitecore.Reflection.ReflectionUtil.InvokeMethod(MethodInfo method, Object[] parameters, Object obj) +91
   Sitecore.Reflection.ReflectionUtil.CallMethod(Object obj, String methodName, Boolean includeNonPublic, Boolean includeInherited, Object[] parameters) +75
   Sitecore.Shell.Applications.ContentManager.ContentEditorPage.OnPreRender(EventArgs e) +120
   System.Web.UI.Control.PreRenderRecursiveInternal() +108
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3410

I did not solve the actual problem, but did come up with a work around. It appears the AD sitecore module in some sense requires write access to AD even though I had disabled almost all parts of the module. I'm not sure why there is no configuration option for a read-only mode.

Regardless, I created some code that finds the user in AD; if found it creates a virtual user, creates a user profile if needed, and updates that profile with the most current info from AD each time the user authenticates with the page.