Byte[] received over socket is invalid[C#]

I have a program with server and client both on different machines. What the program do is send continuous images to server from client. Here client send the datasize first and then the data and similarly server receives the data size in byte[4] and reads the data. Everything is working great but after sometime the datasize byte[] returns some invalid value i.e. -17845811547 or 155488798 and so on. I tried reading the sent and received byte[] and it came to my notice that client is sending the data very well and server is receiving but the server is reading the data sometimes correctly and sometimes it's filling the datasize byte[] with invalid values. Below is the code and invalid result.

Code:

Server -        

private static byte[] receiveFullByte(Socket s)
{            int total = 0;
    int recv;
    byte[] datasize = new byte[4];

    recv = s.Receive(datasize, 0, 4, 0);
    int size = BitConverter.ToInt32(datasize, 0);
    int dataleft = size;
    try
    {
        byte[] data = new byte[size];
        while (total < size)
        {
            if (size > 800000)
            {
                return null;
            }
            recv = s.Receive(data, total, dataleft, 0);
            if (recv == 0)
            {
                break;
            }
            total += recv;
            dataleft -= recv;
        }

        return data;
    }
    catch (Exception ex)
    {
        return null;
    }
}

Client - 

private static void sendDataConti()
{
    if (clientSocket.Connected)
    {
        string request = "Image|" + localipaddress.ipAddressFind() + "||||";
        byte[] clientBufferByte = Encoding.ASCII.GetBytes(request);
        while (true)
        {
            //New Code in use below
            try
            {
                using (Bitmap bmp = PrintScreen())
                {
                    MemoryStream ms = new MemoryStream();
                    bmp.Save(ms, ImageFormat.Jpeg);
                    byte[] buffer = ms.ToArray();
                    byte[] finalArray = new byte[buffer.Length + clientBufferByte.Length];

                    Array.Copy(clientBufferByte, 0, finalArray, 0, clientBufferByte.Length);
                    Array.Copy(buffer, 0, finalArray, clientBufferByte.Length, buffer.Length);

                    SendFullData(finalArray);
                    ms.Dispose();
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
        }
    }
}

private static int SendFullData(byte[] data)
{
    int total = 0;
    int size = data.Length;
    int dataleft = size;
    int sent;

    try
    {
        //send the size of the data
        byte[] datasize = new byte[4];
        datasize = BitConverter.GetBytes(size);
        sent = clientSocket.Send(datasize);
        clientSocket.Send(datasize);
        Console.WriteLine("Size sent " + size);
        logFileWrite(DateTime.Now.ToString("hh:mm:ss.fff") + ": Size sent " + size);
        Thread.Sleep(500);
        //Console.ReadLine();
        //send the image data
        while (total < size)
        {
            sent = clientSocket.Send(data, total, dataleft, SocketFlags.None);
            Console.WriteLine("Data sent " + sent);
            logFileWrite(DateTime.Now.ToString("hh:mm:ss.fff") + ": Data sent " + sent);
            total += sent;
            dataleft -= sent;
        }

        string data2string = Encoding.ASCII.GetString(data);
        string request = data2string.Split('|')[0];
        logFileWrite(DateTime.Now.ToString("hh:mm:ss.fff") + ": Data2String " + request);

        Thread.Sleep(500);
    }
    catch { }

    return total;
}

Result:

Client sent data:

//First data sent
Size sent 126128
Byte 1: 176
Byte 2: 236
Byte 3: 1
Byte 4: 0
Data sent 126128
//Second data sent
Size sent 124521
Byte 1: 105
Byte 2: 230
Byte 3: 1
Byte 4: 0
Data sent 124521

Server received data as:

//First data received which is exactly as sent
Size Received: 126128
Byte 1: 176
Byte 2: 236
Byte 3: 1
Byte 4: 0
//Second data received which is invalid and not same as sent
Size Received: 1734438217
Byte 1: 73
Byte 2: 109
Byte 3: 97
Byte 4: 103

As you can see the first data I have added for you to give an idea that how data is sent and received but during the second data it is not what the client sent. Also do you notice that byte[] values received are invalid. I have no idea what is wrong and from where the server is filling up the byte[] values.