Error deleting Corporate Site

Hi there

I am getting the following error attempting to delete the corporate demo site. I have other sites created. I also get a similar error attempting to delete users created when that demo site was created.

Error deleting site:

Error deleting site: Message: Object reference not set to an instance of an object. Exception type: System.NullReferenceException Stack Trace: at CMS.DataEngine.BaseInfo.GetDependencyObjectType(ObjectDependency dep) at CMS.DataEngine.ObjectTypeInfo.LoadDependendentObjectTypes() at CMS.DataEngine.ObjectTypeInfo.get_DependentObjectTypes() at CMS.DataEngine.BaseInfo.GetRemoveDependenciesList(Boolean getAll, String baseWhere, String connStringContext, List1 processed) at CMS.DataEngine.BaseInfo.RemoveObjectDependenciesAuto(Boolean deleteAll, Boolean clearHashtables) at CMS.DataEngine.BaseInfo.RemoveObjectDependencies(Boolean deleteAll, Boolean clearHashtables) at CMS.DataEngine.AbstractInfo1.DeleteData() at CMS.DataEngine.AbstractInfoProvider2.DeleteInfo(TInfo info) at CMS.DataEngine.BaseInfo.Delete() at CMS.DocumentEngine.TreeNode.DeleteInternal() at CMS.DocumentEngine.TreeNode.Delete(Boolean useDocumentHelper) at CMS.DocumentEngine.DocumentHelper.DeleteDocument(DeleteDocumentSettings settings) at CMS.DocumentEngine.DocumentHelper.DeleteSiteTree(String siteName, TreeProvider tree, OnAfterDocumentDeletedEventHandler deleteCallback, String webRootFullPath) at CMS.Base.AbstractHandler.CallEventHandler[TArgs](EventHandler1 h, TArgs e) at CMS.Base.AbstractHandler.Raise[TArgs](String partName, List1 list, TArgs e, Boolean important) at CMS.Base.AdvancedHandler2.RaiseBefore(TArgs e) at CMS.Base.AdvancedHandler2.RaiseBefore(TArgs e) at CMS.Base.AdvancedHandler2.StartEvent(TArgs e, Boolean allowEvent) at CMS.SiteProvider.SiteDeletionHandler.StartEvent(DeletionInfo deletionInfo, IUserInfo user, CMSActionContext context) at CMS.SiteProvider.SiteDeletionManager.DeleteSite(Object parameter)

Error deleting users:

Object reference not set to an instance of an object.

Any help would be great. This is my first forum post. I am trying this out as an alternative to logging support requests.

Cheers, Brad