第一次写driver,碰到了怪问题!救救我!

驱动程序被装载后,我用windbg监视,能显示调试语句\"Load sys Ok!\"
,但紧跟着出现\"unload driver\"!不知为何?
我用driverstudio2.5 winddk 2000 vc6.0 开发pci 9052驱动!
源码如下:
  
NTSTATUS
DriverEntry(
    PDRIVER_OBJECT  pDriverObject,
    PUNICODE_STRING pRegistryPath
    )
{
    NTSTATUS             status;
    PDEVICE_OBJECT       fdo;
    REGISTRY_INFORMATION RegistryInfo;
   status = STATUS_SUCCESS;
   if (IoIsWdmVersionAvailable(0x01, 0x10) == FALSE)
    {
        if (IoIsWdmVersionAvailable(0x01, 0x00) == TRUE)
        {
            KdPrint((DBG_NAME \"OS supports WDM 1.0 (Windows 98)\\n\"));
            IsOsWinNT = FALSE;
        }
        else
            KdPrint((DBG_NAME \"WARNING - OS does not support WDM 1.0\\n\"));
    }
    else
        KdPrint((\"OS supports WDM 1.10 (Windows 2000 or above)\\n\"));


    KdPrint((DBG_NAME \"Device Registry path = \\\"%ws\\\"\\n\", pRegistryPath->Buffer));


    // Get configuration information from registry
    PlxRegistryInformationGet(
        pRegistryPath,
        &RegistryInfo
        );


    // Fill in the appropriate dispatch handlers
    pDriverObject->DriverUnload                         = DriverUnload;
    pDriverObject->MajorFunction[IRP_MJ_CREATE]         = DispatchCreate;
    pDriverObject->MajorFunction[IRP_MJ_CLOSE]          = DispatchClose;
    pDriverObject->MajorFunction[IRP_MJ_READ]           = DispatchRead;
    pDriverObject->MajorFunction[IRP_MJ_WRITE]          = DispatchWrite;
    pDriverObject->MajorFunction[IRP_MJ_CLEANUP]        = DispatchCleanup;
    pDriverObject->MajorFunction[IRP_MJ_DEVICE_CONTROL] = DispatchIoControl;

    pDriverObject->MajorFunction[IRP_MJ_PNP]            = DispatchPnp;
// pDriverObject->MajorFunction[IRP_MJ_POWER]          = DispatchPower;
    pDriverObject->MajorFunction[IRP_MJ_SYSTEM_CONTROL] = DispatchSystemControl;
    pDriverObject->DriverExtension->AddDevice           = AddDevice;

    mgCommonBuffer.pMdl                = NULL;
    mgCommonBuffer.pKernelVa           = NULL;
    mgCommonBuffer.PciMem.PhysicalAddr = (U32)-1;
    mgCommonBuffer.PciMem.UserAddr     = (U32)-1;
    mgCommonBuffer.PciMem.Size         = 0;

KdPrint((DBG_NAME \"Load Sys Ok! \")
    return STATUS_SUCCESS;
}