C++程序运行错误

本来程序运行的很好，我用windows media player 播放了一下mid文件再运行的时候就播放不了了，有高手指点一下！
/*播放声音*/
    if(OpenParms1.wDeviceID)
        mciSendCommand(OpenParms1.wDeviceID, MCI_CLOSE, MCI_WAIT, (DWORD)&OpenParms1);
    if(OpenParms2.wDeviceID)
        mciSendCommand(OpenParms2.wDeviceID, MCI_CLOSE, MCI_WAIT, (DWORD)&OpenParms2);

    //打开   
    //MCI_OPEN_PARMS OpenParms;
    OpenParms1.lpstrDeviceType = (LPCSTR)MCI_DEVTYPE_WAVEFORM_AUDIO;//MIDI设备类型
    OpenParms1.lpstrElementName = (LPCSTR)"res\\start.wav";//文件名
    OpenParms1.wDeviceID = 0;//设备标识号(用于和其他设备区分)
    mciSendCommand(NULL, MCI_OPEN, MCI_OPEN_ELEMENT|MCI_NOTIFY, (DWORD)&OpenParms1);
    //播放
    MCI_PLAY_PARMS PlayParms;
    PlayParms.dwFrom = 0;//从头开始播放
    mciSendCommand(OpenParms1.wDeviceID, MCI_PLAY, MCI_FROM, (DWORD)&PlayParms);

    OpenParms2.lpstrDeviceType = (LPCSTR)MCI_DEVTYPE_SEQUENCER;//WAV设备类型
    OpenParms2.lpstrElementName = (LPCSTR)"res\\bg.mid";//文件名
    OpenParms2.wDeviceID = 0;//设备标识号(用于和其他设备区分)
    mciSendCommand(NULL, MCI_OPEN, MCI_OPEN_ELEMENT|MCI_NOTIFY, (DWORD)&OpenParms2);
    //播放
    PlayParms.dwFrom = 0;//从头开始播放
    mciSendCommand(OpenParms2.wDeviceID, MCI_PLAY, MCI_FROM, (DWORD)&PlayParms)