Umbraco 4.5.2

When saving members or logging in the following error occurs:-

Any help would be great.

Cheers

Aron

An item with the same key has already been added

System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) +12673712
   UmbracoExamine.LuceneExamineIndexer.GetDataToIndex(XElement node, String type) +1910
   UmbracoExamine.MemberLuceneExamineIndexer.GetDataToIndex(XElement node, String type) +93
   UmbracoExamine.LuceneExamineIndexer.AddSingleNodeToIndex(XElement node, String type) +652
   UmbracoExamine.LuceneExamineIndexer.ReIndexNode(XElement node, String type) +305
   Examine.ExamineManager._ReIndexNode(XElement node, String type, IEnumerable`1 providers) +206
   Examine.ExamineManager.ReIndexNode(XElement node, String type, IEnumerable`1 providers) +71
   UmbracoExamine.UmbracoEventManager.Member_AfterSave(Member sender, SaveEventArgs e) +412
   umbraco.cms.businesslogic.member.SaveEventHandler.Invoke(Member sender, SaveEventArgs e) +0
   umbraco.cms.businesslogic.member.Member.FireAfterSave(SaveEventArgs e) +131
   umbraco.cms.businesslogic.member.Member.Save() +478
   umbraco.providers.members.UmbracoMembershipProvider.ValidateUser(String username, String password) +942
   System.Web.UI.WebControls.Login.AuthenticateUsingMembershipProvider(AuthenticateEventArgs e) +225
   System.Web.UI.WebControls.Login.AttemptLogin() +166
   System.Web.UI.WebControls.Login.OnBubbleEvent(Object source, EventArgs e) +93
   System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +52
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3691