usb驱动高手请进！

各位大虾：你们好！！！！
我的usb驱动为何AddDevice时创建设备IoCreateDevice总是失败。用softice 也看不到返回值。帮帮我把！！！ :( :(

把代码贴出来，才知道呀

请看我的代码

NTSTATUS PnpAddDevice(
    IN PDRIVER_OBJECT pDriverObject,
    IN PDEVICE_OBJECT PhysicalDeviceObject
    )

{
    NTSTATUS                ntStatus = STATUS_SUCCESS;
    PDEVICE_OBJECT          deviceObject = NULL;
    PDEVICE_EXTENSION       pDevExt;  
    //ULONG i;
static int ulDeviceNumber = 0;
  
    CUString devName("\\Device\\Usb9602");
devName += CUString(ulDeviceNumber);

ntStatus = IoCreateDevice( pDriverObject,
sizeof(DEVICE_EXTENSION),
&(UNICODE_STRING)devName,
FILE_DEVICE_UNKNOWN,
0, TRUE,
&deviceObject);
if (!NT_SUCCESS(ntStatus))
return ntStatus; //程序跳出

// Choose to use BUFFERED_IO
deviceObject->Flags |= DO_DIRECT_IO;
// Initialize the Device Extension
pDevExt = (PDEVICE_EXTENSION)deviceObject->DeviceExtension;
pDevExt->pDevice = deviceObject; // back pointer
pDevExt->DeviceNumber = ulDeviceNumber;
pDevExt->ustrDeviceName = devName;

pDevExt->PhysicalDeviceObject=PhysicalDeviceObject;
pDevExt->TopOfStackDeviceObject = IoAttachDeviceToDeviceStack(deviceObject,PhysicalDeviceObject);
//pDevExt->Irq = Irq;

// Form the symbolic link name
CUString symLinkName("\\??\\usb9602n");
symLinkName += CUString(ulDeviceNumber+1); // 1 based
pDevExt->ustrSymLinkName = symLinkName;

// Now create the link name
ntStatus =
IoCreateSymbolicLink( &(UNICODE_STRING)symLinkName,
 &(UNICODE_STRING)devName );
if (!NT_SUCCESS(ntStatus)) {
// if it fails now, must delete Device object
IoDeleteDevice( deviceObject );
return ntStatus;
}
    deviceObject->Flags &= ~DO_DEVICE_INITIALIZING;
    return ntStatus;
}

ntStatus = IoCreateDevice( pDriverObject,
sizeof(DEVICE_EXTENSION),
&(UNICODE_STRING)devName,
FILE_DEVICE_UNKNOWN,
0,
FALSE,  //这里是保留给系统的，驱动应该设置成FALSE
&deviceObject);
if (!NT_SUCCESS(ntStatus))