serial Port not working properly - VS2005 on Windows 7

Question

Hi,

Recently I got a Desktop with Windows 7 Ultimate.

I installed VS2005 which I was using for more than four years on XP Machine.  

My application which was working fine on XP is not working on windows 7 machine.

When bytes are read from the Serial Port ( I am using .NET 2.0 Serial Port ) BytesToRead is not getting reduced. it keeps increasing and eventually buffer is full and stops receiving any more data.

am I missing anything ? 

code snippet which reads from serial port is given below.

        public void PSerialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)

        {

            ushort addr, Data,crc;

            byte cmd;

            char ch;

            do

            {

                CharReceived = ch = (char)this.ReadByte();  // read char from port

            } while (ch != '@');

            Packet[0] = (byte)ch;

            this.Read(Packet, 1, 13);

 

            crc = CRCGenerator.GenerateCRC(Packet, 10, 0);

            cmd = (byte)toint((char)Packet[1]);

            addr = (ushort)( toint((char)Packet[10]) * 16 + toint((char)Packet[11]));

            addr = (ushort)(addr * 256 + toint((char)Packet[12]) * 16 + toint((char)Packet[13]));

            if (crc != addr)  // if crc is non zero then ignore packet.

            {

                return;

            }

            addr = (ushort)(toint((char)Packet[2]) * 16 + toint((char)Packet[3]));

            addr = (ushort)(addr * 256 + toint((char)Packet[4]) * 16 + toint((char)Packet[5]));

            Data = (ushort)(toint((char)Packet[6]) * 16 + toint((char)Packet[7]));

            Data = (ushort)(Data * 256 + toint((char)Packet[8]) * 16 + toint((char)Packet[9]));

            rRPktNo++;

            if (rRPktNo == 128)

            {

                rRPktNo = 0;

            }

            DataReceivedEventArgs de = new DataReceivedEventArgs(cmd,addr,Data);

            OnDreceived(de);   // activate event

            

            return;

        }

the application was deployed and working fine on four different XP machines, for more than three years.