My program is rather extensive, however, whenever I go to debug my main function which utilizes my main class (which in turn uses various other classes) I get a seg fault wherever I put the break point. Here's my main file.

Code:
#include <cstdlib>
#include <fstream>
#include <iostream>
#include <string>
#include <sstream>
#include "CheckIn.h"
#include "Customers.h"

using namespace std;

int main()
{
    ifstream infile;
    infile.open("in.txt");
    CheckIn Hotel;

    if (infile.fail())
    {
        cout << "Cannot open file, program terminated." << endl;
        exit(1);
    }
    string lineread; //holds a line from the input file
    while(getline(infile, lineread))
    {
        string sub; //holds the individual words within lineread
        istringstream iss(lineread);
        while (iss >> sub)
        {
            if (sub == "add")
            {
                Customer person;
                string tempfirst, templast, temptype;
                int tempnights;
                iss >> tempfirst >> templast >> temptype >> tempnights;
                Hotel.add(tempfirst, templast, temptype, tempnights);

            }
        }
    }
    //used for testing purposes
    cout << Hotel.Platinum.CustArray[0].firstname << endl; 
    cout << Hotel.NonElite.backPtr->person.firstname << endl;
    return 0;
}
Basically, wherever I put a break point, while debugging the file, I get a seg fault. However, that said I can run the program and it doesn't crash, so I am a bit confused at this behavior. If needed I can post my entire code. I am wondering if anyone knows of something within C++ that could cause this kind of behavior. Thanks, and let me know if you want my entire code.