C++ Interpreter for Custom Language Has Stopped Working

[cppietime]

I wrote what is supposed to be a custom language interpreter of sorts. The first few commands worked, but then, after I added a few more commands, and had to change the ifstream read to a global opening it in main(), using getline() causes it to stop working. Why is this? I used a debugger and:
Access Violation(Segmentation Fault) raised in program.
Why is this? What is causing this? Is something wrong with the way I did that? The reason it is a global now is so that the JMP command works, as well as SIZ and SIN, so that those commands can getline() a number of times to skip those lines, and JMP can use seekg() to jump to another part of the code. Also, if I remove those commands and declare read in main(), it works and runs through, but skips some characters when reading the input file. I have absolutely no idea why? Strangely, it skips 3 on the first line, 2 on the second, 1 on the third, and none on the fourth. Please help.

  #include<iostream>
#include<fstream>
#include<ctype.h>
#include<conio.h>
#include<string>
#include<vector>
using namespace std;

#define ADD "ADD"
#define SUB "SUB"
#define SET "SET"
#define ICO "ICO"
#define CCO "CCO"
#define IUI "IUI"
#define CUI "CUI"
#define COP "COP"
#define MUL "MUL"
#define DIV "DIV"
#define MOD "MOD"
#define TPC "TPC"
#define PKP "PKP"
#define SIZ "SIZ"
#define SIN "SIN"
#define JMP "JMP"

/*struct expr{
       string torun;
       int param1;
       int param2;       
};*/

ifstream read;
int* posoflines;
int linesread;
int mem[16];
bool cont;
void parse(string line);
void run(string com, int first, int second);

int main(int argc, const char* argv[]){
    cout << "Main function loaded." << endl;
    /*if(argc<=1){
                cout << "Filename required.";
                getch();
                return 0;
    }*///If no filename supplied, terminate program.
    cout << "Filename recieved." << endl;
    cont=true;
    linesread=0;
    string filename="addthese.txt";
    string sStore;
    for(int x=0; x<16; x++){ //Allocate 0 to all spots of memory.
            mem[x]=0;
    }
    read.open(filename.c_str()); //Open file.
    cout << "File loaded." << endl;
    if(read.good()){
                    cout << "File good." << endl;
    }
    read >> sStore;
    cout << "First line read: "  << sStore << endl;
    int lines=atoi(sStore.c_str());
    cout << "Converted to int." << endl;
    posoflines = new int[lines];
    cout << "Array initialized." << endl;
    while(getline(read, sStore) && cont){ //Call parse fuction for each line.
    posoflines[linesread++]=read.tellg();
    parse(sStore);
    cout << "Parsing line" << endl;
    }
    getch(); //Pause at end of program.
}

void parse(string line){
     char cur;
     string command;
     string store = "";
     int left=0;
     int right=0;
     int curpos=0;
     int iCur=0; //Allocate all registers as blank.
     for(int i=0; i<line.length(); i++){
             cur = line[i]; //Set cur.
             if(isspace(cur)){ //If it is a space.
                              if(curpos==0){
                                            command = store;
                                            curpos++;
                              }else if(curpos==1){
                                    for(int e=0; e<store.length(); e++){
                                            int quick=(store[e]-'0');
                                            iCur*=10;
                                            iCur+=quick;
                                    }
                                    left = iCur;
                                    iCur=0;
                                    curpos++;
                              }else if(curpos==2){
                                    for(int e=0; e<store.length(); e++){
                                            int quick=(store[e]-'0');
                                            iCur*=10;
                                            iCur+=quick;
                                    }
                                    right = iCur;
                              } //Store in appropriate register.
                              store=""; //Reset store.
             }else{ //If not a space.
                   store+=cur; //Append to store.
             }
             cout << "Character Parsed:" << cur << endl;
     }
     run(command, left, right);
}

void run(string com, int first, int second){
     string nulled;
     cout << "Running command" << endl;
     if(com==SET){
                  mem[first]=second;
     }else if(com==ADD){ //Add command.
           mem[first]+=mem[second];
     }else if(com==SUB){ //Subtract command.
           mem[first]-=mem[second];
     }else if(com==ICO){ //Integer Console Ouput command.
           cout << mem[first];
     }else if(com==CCO){ //Character Console Output command.
           cout << (char)mem[first];
     }else if(com==IUI){ //Integer User Input command.
           cin >> mem[first];
     }else if(com==CUI){ //Character User Input command.
           mem[first]=getch();
     }else if(com==COP){ //Copy command.
           mem[first]=mem[second];
     }else if(com==MUL){ //Multiply command.
           mem[first]*=mem[second];
     }else if(com==DIV){ //Divide command.
           mem[first]/=mem[second];
     }else if(com==MOD){ //Modulo command.
           mem[first]%=mem[second];
     }else if(com==TPC){ //Terminate Program at Command command.
           cont=false;
     }else if(com==PKP){ //Pause until Key Pressed command.
           getch();
     }else if(com==SIZ){ //Skip If Zero command.
           if(mem[first]==0){
                             for(int j=0; j<second; j++){
                                     getline(read, nulled);
                             }
           }
     }else if(com==SIN){ //Skip If Non-Zero command.
           if(mem[first]!=0){
                             for(int j=0; j<second; j++){
                                     getline(read, nulled);
                             }
           }
     }else if(com==JMP){
           read.seekg(posoflines[first]);
     }
}

Also, if you leave an answer, please don't just say which line is causing a problem or something like that, tell me what I need to change my code to WITH EXAMPLE CODE.

addthese.txt:

4
SET 0 4
SET 1 1
SUB 0 1
ICO 0 0 

(the second 0 in ICO is just a filler space)
But the program reads it as:

 0 4
T 1 1
UB 0 1
ICO 0 0

Why?

EDIT:
Okay, I fixed the problem where it skips characters, and I'm going to use a completely different method for jumping now, but I still need to know why I can't use getline() if ifstream read is declared as a global. Any ideas?