I have installed locally on my machine, and everything is fine - But as soon as I try to save and PUBLISH I get the following - Save on its own is fine, but publishing causes the error.  So its something to do with the onpublish event / DateFolders, as even though I get this message the node is published when I refresh the page, but no Date Folders?

 The given key was not present in the dictionary. 

            

             Description: An unhandled exception occurred during 
the execution of the current web request. Please review the stack trace 
for more information about the error and where it originated in the 
code.

            



             Exception Details: System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.



            Source Error: 



            

               

                  

                      

An unhandled exception was generated during the execution of the current
 web request. Information regarding the origin and location of the 
exception can be identified using the exception stack trace below.

                  
               
            

            


            Stack Trace: 



            

               

                  

                      
[KeyNotFoundException: The given key was not present in the dictionary.]
   System.Collections.Generic.Dictionary`2.get_Item(TKey key) +4243807
   umbraco.library.niceUrlDo(Int32 nodeID, Int32 startNodeDepth) +461
   umbraco.library.NiceUrlFullPath(Int32 nodeID) +53
   Umlaut.Umb.Blog.EventHandlers.Autoping.Document_AfterPublish(Document sender, PublishEventArgs e) +565
   umbraco.cms.businesslogic.web.Document.FireAfterPublish(PublishEventArgs e) +130
   umbraco.cms.businesslogic.web.Document.PublishWithResult(User u) +3098
   umbraco.cms.presentation.editContent.Publish(Object sender, EventArgs e) +508
   System.EventHandler.Invoke(Object sender, EventArgs e) +0
   umbraco.controls.ContentControl.savePublish(Object Sender, ImageClickEventArgs e) +165
   System.Web.UI.WebControls.ImageButton.OnClick(ImageClickEventArgs e) +134
   System.Web.UI.WebControls.ImageButton.RaisePostBackEvent(String eventArgument) +165
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3691