紧急求救：虚拟化DMA错误

各位大侠请指点:
为什么我在编写DMA的VXD程序时(用VTOOLSD),调试的时候（用VTOOLSD自带的DEBUG)总是出现DMA不能虚拟化的消息.有时出现：同样的代码，虚拟同样的DMA通道只是文件名不一样，但是在一个程序中能虚拟化，在另一个却不能的情况。有时出现调试时，先出现蓝屏，手动回到WINDOWS后，再次调试才虚拟成功。下面是我的程序
请指教，万分感谢！（编译能通过）


／／／／CPP文件
#define DEVICE_MAIN
#include \"dmano.h\"
Declare_Virtual_Device(DMANO)
#undef DEVICE_MAIN
DmanoDMAChannel* pchannel;
DmanoVM::DmanoVM(VMHANDLE hVM) : VVirtualMachine(hVM) {}

DmanoThread::DmanoThread(THREADHANDLE hThread) : VThread(hThread) {}

BOOL DmanoDevice::OnSysDynamicDeviceInit()
{
pchannel=new DmanoDMAChannel();
if(pchannel->hook())
{
dout<<\"hook success\"<<endl;
}
else return FALSE;
return TRUE;
}

BOOL DmanoDevice::OnSysDynamicDeviceExit()
{
if(pchannel)
{
pchannel->unhook();
dout<<\"unhook success\"<<endl;
delete pchannel;
}
return TRUE;
}

void DmanoDMAChannel::handler(VMHANDLE hVM)
{
dout<<\"I am a college student\";
}
DmanoDMAChannel::DmanoDMAChannel(): VDMAChannel(1)
{
}



／／／／H文件
// DMANO.h - include file for VxD DMANO

#include <vtoolscp.h>

#define DEVICE_CLASS DmanoDevice
#define DMANO_DeviceID UNDEFINED_DEVICE_ID
#define DMANO_Init_Order UNDEFINED_INIT_ORDER
#define DMANO_Major 1
#define DMANO_Minor 0

class DmanoDevice : public VDevice
{
public:
virtual BOOL OnSysDynamicDeviceInit();
virtual BOOL OnSysDynamicDeviceExit();
};

class DmanoVM : public VVirtualMachine
{
public:
DmanoVM(VMHANDLE hVM);
};

class DmanoThread : public VThread
{
public:
DmanoThread(THREADHANDLE hThread);
};


class DmanoDMAChannel:public VDMAChannel
{
public:
DmanoDMAChannel();
void handler(VMHANDLE hVM);
};