When unchecking the Audience Targeting checkbox on a survey we get the following error: Operation is not valid due to the current state of the object. at Microsoft.SharePoint.SPFieldCollection.Delete(String strName) at Microsoft.SharePoint.Portal.Audience.AdminUI.ListEnableTargetingPage.BtnSave_Click(Object sender, EventArgs e) at System.Web.UI.WebControls.Button.OnClick(EventArgs e) at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) ANY IDEA WHY THIS MIGHT BE HAPPENING?