Can't delete custom entity[CRMVersion: 4.0.7333.2935]

>Crm Exception: Message: Entity Name specified in FetchXml does not match the entity name in the EntityExpression, ErrorCode: -2147217112
# CRM Tracing Version 2.0
# LocalTime: 2011-08-30 23:11:02.9
# Categories: *
# CallStackOn: Yes
# ComputerName: xxxx
# CRMVersion: 4.0.7333.2935
# DeploymentType: OnPremise
# ScaleGroup: 
# ServerRole: AppServer, AsyncService, DiscoveryService, WebService, ApiServer, HelpServer, DeploymentService

[2011-08-30 23:11:02.9] Process: w3wp |Organization:450d97a9-8f18-4966-b33d-32af6d161315 |Thread: 3 |Category: Platform.Metadata |User: 00000000-0000-0000-0000-000000000000 |Level: Error | EntityService.Delete
	at EntityService.Delete(Guid entityId, ExecutionContext context)
	at EntityService.Delete(Guid entityId)
	at EntityDelete.Execute(IUser user, Guid entityId)
	at SystemCustomization.DeleteEntity(Guid entityId)
	at RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner)
	at RuntimeMethodHandle.InvokeMethodFast(Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner)
	at RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks)
	at RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
	at LogicalMethodInfo.Invoke(Object target, Object[] values)
	at WebServiceHandler.Invoke()
	at WebServiceHandler.CoreProcessRequest()
	at SyncSessionlessHandler.ProcessRequest(HttpContext context)
	at CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
	at HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
	at ApplicationStepManager.ResumeSteps(Exception error)
	at HttpApplication.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData)
	at HttpRuntime.ProcessRequestInternal(HttpWorkerRequest wr)
	at HttpRuntime.ProcessRequestNoDemand(HttpWorkerRequest wr)
	at ISAPIRuntime.ProcessRequest(IntPtr ecb, Int32 iWRType)>EntityService.Update caught exception: System.NullReferenceException: Object reference not set to an instance of an object.
 at Microsoft.Crm.ObjectModel.OrganizationUIService.LabelLoaderPublished.LoadMetadataLabel(Int32 entityType, String attributeName, ExecutionContext context)
 at Microsoft.Crm.ObjectModel.OrganizationUIService.LabelLoader.LoadCellLabel(Guid cellObjectId, String cellObjectColumnName, Int32 objectType, String attributeName, ExecutionContext context)
 at Microsoft.Crm.ObjectModel.OrganizationUIService.InsertFormLabels(IBusinessEntity entity, ILabelLoader labelLoader, ExecutionContext context)
 at Microsoft.Crm.ObjectModel.OrganizationUIService.Retrieve(BusinessEntityMoniker moniker, EntityExpression entityExpression, ExecutionContext context)
 at Microsoft.Crm.ObjectModel.OrganizationUIService.GetIdsOfDeletedNodes(List`1 objectIds, String newFormXml, BusinessEntityMoniker moniker, ExecutionContext context)
 at Microsoft.Crm.ObjectModel.OrganizationUIService.PublishFormLabels(IBusinessEntity entity, ExecutionContext context)
 at Microsoft.Crm.Metadata.OrganizationUIHelper.DeleteHelper(Int32 objectTypeCode, ExecutionContext context)
 at Microsoft.Crm.Metadata.EntityService.DeleteUIData(Int32 objectTypeCode, ExecutionContext context)
 at Microsoft.Crm.Metadata.EntityService.Delete(Guid entityId, ExecutionContext context)
[2011-08-30 23:11:03.1] Process: w3wp |Organization:450d97a9-8f18-4966-b33d-32af6d161315 |Thread: 3 |Category: Application |User: 00000000-0000-0000-0000-000000000000 |Level: Error | ErrorInformation.LogError
	at ErrorInformation.LogError()
	at ErrorInformation..ctor(Exception exception, Uri requestUrl, Boolean logError)
	at ErrorInformation..ctor(Exception exception, Uri requestUrl)
	at AppWebService.CreateSoapException(Exception innerException)
	at SystemCustomization.DeleteEntity(Guid entityId)
	at RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner)
	at RuntimeMethodHandle.InvokeMethodFast(Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner)
	at RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks)
	at RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
	at LogicalMethodInfo.Invoke(Object target, Object[] values)
	at WebServiceHandler.Invoke()
	at WebServiceHandler.CoreProcessRequest()
	at SyncSessionlessHandler.ProcessRequest(HttpContext context)
	at CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
	at HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
	at ApplicationStepManager.ResumeSteps(Exception error)
	at HttpApplication.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData)
	at HttpRuntime.ProcessRequestInternal(HttpWorkerRequest wr)
	at HttpRuntime.ProcessRequestNoDemand(HttpWorkerRequest wr)
	at ISAPIRuntime.ProcessRequest(IntPtr ecb, Int32 iWRType)>MSCRM Error Report:
--------------------------------------------------------------------------------------------------------
Error: Object reference not set to an instance of an object.

Error Message: Object reference not set to an instance of an object.

Source File: Not available

Line Number: Not available

Request URL: http://crm.xxx.com/AppWebServices/SystemCustomization.asmx

Stack Trace Info: [NullReferenceException: Object reference not set to an instance of an object.]
 at Microsoft.Crm.ObjectModel.OrganizationUIService.LabelLoaderPublished.LoadMetadataLabel(Int32 entityType, String attributeName, ExecutionContext context)
 at Microsoft.Crm.ObjectModel.OrganizationUIService.LabelLoader.LoadCellLabel(Guid cellObjectId, String cellObjectColumnName, Int32 objectType, String attributeName, ExecutionContext context)
 at Microsoft.Crm.ObjectModel.OrganizationUIService.InsertFormLabels(IBusinessEntity entity, ILabelLoader labelLoader, ExecutionContext context)
 at Microsoft.Crm.ObjectModel.OrganizationUIService.Retrieve(BusinessEntityMoniker moniker, EntityExpression entityExpression, ExecutionContext context)
 at Microsoft.Crm.ObjectModel.OrganizationUIService.GetIdsOfDeletedNodes(List`1 objectIds, String newFormXml, BusinessEntityMoniker moniker, ExecutionContext context)
 at Microsoft.Crm.ObjectModel.OrganizationUIService.PublishFormLabels(IBusinessEntity entity, ExecutionContext context)
 at Microsoft.Crm.Metadata.OrganizationUIHelper.DeleteHelper(Int32 objectTypeCode, ExecutionContext context)
 at Microsoft.Crm.Metadata.EntityService.DeleteUIData(Int32 objectTypeCode, ExecutionContext context)
 at Microsoft.Crm.Metadata.EntityService.Delete(Guid entityId, ExecutionContext context)
 at Microsoft.Crm.Metadata.EntityService.Delete(Guid entityId)
 at Microsoft.Crm.Application.WebServices.SystemCustomization.EntityDelete.Execute(IUser user, Guid entityId)
 at Microsoft.Crm.Application.WebServices.SystemCustomization.SystemCustomization.DeleteEntity(Guid entityId)