Reading Serial Port

After reading a lot about threads, now I can understand the example
from http://www.flounder.com/serial.htm.

I need to comunicate with a device that I tested and works OK, it just
sends frames at 9600 bauds (other programs receive their frames as
expected).

In my firsts attempts I was receiving corrupted frames, but I think I
corrected it adjusting the dcb to:
dcb.DCBlength = sizeof(dcb);
  dcb.BaudRate = CBR_9600;
  dcb.fBinary = TRUE;
  dcb.fParity = TRUE;
  dcb.fOutxCtsFlow = FALSE;
  dcb.fOutxDsrFlow = FALSE;
  dcb.fDtrControl = DTR_CONTROL_DISABLE;
  dcb.fDsrSensitivity = FALSE;
  dcb.fTXContinueOnXoff = FALSE;
  dcb.fOutX = FALSE;
  dcb.fInX = FALSE;
  dcb.fErrorChar = FALSE;
  dcb.fNull = FALSE;
  dcb.fRtsControl = RTS_CONTROL_DISABLE;
  dcb.fAbortOnError = FALSE;
  dcb.XonLim = 2048; //I think just a 0 will work,
so I have all flow controls at false
  dcb.XoffLim = 512; //I think just a 0 will
work, so I have all flow controls at false
  dcb.ByteSize = 8;
  dcb.Parity = ODDPARITY;
  dcb.StopBits = 0;
  dcb.XonChar = 0;
  dcb.XoffChar = 0;
  dcb.ErrorChar = 0;
  dcb.EofChar = 0;
  dcb.EvtChar = 0;

Ok, mostly all corrupted bytes dissapeared.
This is the frame I should receive (16 bytes length):
af 0a 00 00 00 00 00 00 00 00 00 00 00 00 00 b9

My first problem comes with a curious fact:
I always get the frame 16th cutted!!
Sometimes I just receive its last byte (b9), or some middle 0x00
ommited... other times af and 0a with some 0's...

Example:

af 0a 00 00 00 00 00 00 00 00 00 00 00 00 00 b9 //15th frame
00 00 b9 //
16th frame
af 0a 00 00 00 00 00 00 00 00 00 00 00 00 00 b9 //17th frame

What's wrong??? I found that 256/16 (bytes) = 16 frames. Is this
casual?? Note that this only happens in frame 16th, no error with
frame number 32 or other.
Here my reader handler where I read single bytes every loop:

void MyThread::OnReadData( WPARAM wParam, LPARAM )
{
    BOOL reading = TRUE;
    DWORD dwError = 0;
    DWORD bytesRead;
    COMSTAT comState;
    HANDLE hArray[2]; //Un array de eventos
    hArray[0] = ShutdownEvent;
    hArray[1] = ovReader.hEvent;

    //Extrae el estado del puerto y limpia el flag de error para
siguientes operaciones I/O
    ClearCommError( hComm, &dwError, &comState );

    while( reading )
    {
        unsigned char buffer;

        BOOL ok = ::ReadFile( hComm, &buffer, 1, &bytesRead, &ovReader );
        if( !ok ) //ERROR
        {
            DWORD err = GetLastError();
            if( err!=ERROR_IO_PENDING )
            {
                TRACE("Error lectura.\n");
                reading = FALSE;
                continue; //Nos saltamos el switch
            }

            //Ahora esperamos a que ocurra Shutdown o ovReader
            DWORD result = WaitForMultipleObjects( 2, hArray, FALSE,
INFINITE );
            switch( result )
            {
                //Esperar
                case WAIT_OBJECT_0: //Shutdown
                                TRACE("SHUTDOWN!\n");
                                reading = FALSE;
                                continue;

                case WAIT_OBJECT_0+1: // I/O complete!
                                //TRACE("DATA RECEIVED!.\n");
                                ok = GetOverlappedResult( hComm, &ovReader, &bytesRead,
TRUE );
                                if(!ok )
                                {
                                    TRACE( "ERROR getoverlapped result.\n");
                                    reading = FALSE;
                                    continue;
                                }
                                else
                                {
                                    TRACE( "Received with delay: bytesRead:%d buffer:%d
\n",bytesRead, buffer);
                                }
                                break;
            }
        }
        else
        {
            TRACE("\nOK==TRUE -->bytesRead:%d buffer:%d\n",bytesRead, buffer);
        }

        if( bytesRead>0 )
        {
            this->notificador->PostMessage(UWM_DATA_READ, (WPARAM)buffer);
        }
        else //Nothing readed
            continue;
        }
}