IRP_MJ_INTERNAL_DEVICE_CONTROL problem

H

I'm currently developing a filter driver, but I still encounter this problem in my IRP_MJ_INTERNAL_DEVICE_CONTROL handler. That's my code

NTSTATUS MyDispatchInternalDeviceControl(IN PDEVICE_OBJECT pDeviceObject, IN PIRP Irp)
{
PDEVICE_EXTENSION pDeviceEx;
PIO_STACK_LOCATION IrpSp = NULL;

IrpSp = IoGetCurrentIrpStackLocation(Irp);

IoCopyCurrentIrpStackLocationToNext( Irp );
pDeviceEx = (PDEVICE_EXTENSION)pDeviceObject->DeviceExtension;
return IoCallDriver(pDeviceEx->pLowerDeviceObject, Irp ); //crashe
}

When I call IoCallDriver the system crashes with KERNEL_MODE_EXCEPTION (8e). Does anyone know why

Thanks a lo
mosquitooth