SerialPort Application Help.

Im Porting over an application that i made for the Arduino. The application should works as follows:

Steps:

• Receive Serial Data. (Always ends in rn)
• Parse out parts of the data
• Check files on Sdcard for match. if no match stop here. 
• Apply the Parsed Data to the initialization of an instance of a Struct.
• Add the Struct to an ArrayList.
• if the Structs existed for a certain amount of time, Signal the Serial port.
• After a long period of time, remove the structs.

I Made a flowchart to explain the Application:

I have the Application working, but im experiencing Data Loss issues somewhere along the Line.

Here is my Actual Request Struct:

class Request{    public int Location_index { get; set; }    public char SubLocation { get; set; }    public int Details_index { get; set; }    public long Start_time { get; set; }    public int Level { get; set; }    public Request(int locIndex, char SubLoc, int Detail)    {        Location_index = locIndex;        SubLocation = SubLoc;        Details_index = Detail;        Start_time = DateTime.Now.Ticks;        Level = 0;    }    public override bool Equals(object obj)    {        Request ncs = obj as Request;        if (ncs == null) return false;        else        {            if (this.Location_index != ncs.Location_index) return false;            if (this.SubLocation != ncs.SubLocation) return false;            if (this.Details_index != ncs.Details_index) return false;            return true;        }    }}