Binary Tree pointers printing out memory address?

[Sam 07]

I am having trouble with a program that I am writing. It is supposed to play the 20 questions game, and save the data in a binary tree. It also learns if it is wrong. I have to read the data in from a file to the tree when the program runs and save it back when it exits. The problem I am having, is that when it prints out the contents of any part of the tree, it is printing out what looks like a memory address, or a random spot in memory as if the pointer has been set to a random memory address. Any help?
tree.cpp:

/*
 *  tree.cpp
 *  Program 4
 *
 *  Created by Sam on 4/6/11.
 *  Copyright 2011 __MyCompanyName__. All rights reserved.
 *
 */

#include "tree.h"

Tree::Tree()
{
	root = new Node;
	loc = root;
};

void Tree::play()
{
	while (!loc->isLeaf)
	{
		cout << loc->content << "(y/n)" << endl;
		string ans;
		cin >> ans;
		while (ans != "y" && ans != "Y" && ans != "n" && ans != "N")
		{
			cout << "Please choose 'y' or 'n'" << endl;
			cin >> ans;
		}
		if (ans == "y" || ans == "Y")
			loc = loc->yes;
		else 
			loc = loc->no;
	}
	cout << "Is your animal a " << loc->content << "?" << endl;
	cout << "Correct? (y/n)" << endl;
	char ans1;
	cin >> ans1;
	while (ans1 != 'y' && ans1 != 'Y' && ans1 != 'n' && ans1 != 'N')
	{
		cout << "Please choose 'y' or 'n'" << endl;
		cin >> ans1;
	}
	
	if (ans1 != 'y' || ans1 != 'Y')
		insert();
};

void Tree::resetLoc()
{
	loc = root;
};

void Tree::saveTree()
{
	ofstream save;
	save.open("tree.dat", ios::app);
	//loc = root;  --put this right beore this function is called
	save << loc->isLeaf << loc->content << endl;
	
	if (!loc->isLeaf)
	{
		parent = loc;
		loc = loc->yes;
		saveTree();
		loc = parent;
		loc = loc->no;
		saveTree();
	}
	save.close();	
}
	 
void Tree::fillTree()
{
	string temp;
	ifstream read;
	read.open("tree.dat");
	getline(read, temp);
	if (temp[1]=='0')
		loc->isLeaf = false;
	else 
		loc->isLeaf = true;
	loc->content=temp.substr(1);
	
	if (!loc->isLeaf)
	{
		loc->yes = new Node;
		parent = loc;
		loc = loc->yes;
		fillTree();
		loc = parent;
		loc = loc->no;
		fillTree();
		loc = parent;
	}
	read.close();
};

void Tree::insert()
{
	cout << "What were you thinking of?" << endl;
	string newName;
	cin >> newName;
	cout << "What would distinguish a " << newName;
	cout << "from a " << loc->content << "?" << endl;
	string newQuestion;
	cin >> newQuestion;
	cout << "What is the answer to that question for a " << newName <<"? (y/n)" << endl;
	string answer;
	cin >> answer;
	while (answer != "y" && answer != "Y" && answer != "n" && answer != "N")
	{
		cout << "Please choose 'y' or 'n'" << endl;
		cin >> answer;
	}
	if (answer == "y" || answer == "Y")
	{
		loc->yes = new Node;
		loc->yes->content = newName;
		loc->yes->isLeaf = true;
		loc->no = new Node;
		loc->no->content = loc->content;
		loc->no->isLeaf = true;
	}
	else 
	{
		loc->no = new Node;
		loc->no->content = newName;
		loc->no->isLeaf = true;
		loc->yes = new Node;
		loc->yes->content = loc->content;
		loc->yes->isLeaf = true;
	}
	loc->isLeaf = false;
	loc->content = newQuestion;
};

tree.h:

/*
 *  tree.h
 *  Program 4
 *
 *  Created by Sam on 4/6/11.
 *  Copyright 2011 __MyCompanyName__. All rights reserved.
 *
 */
#include <iostream>
#include <fstream>
#include <string>
using namespace std;

class Tree
{
public:
	void play();
	void saveTree();
	void insert();
	void fillTree();
	void resetLoc();
	Tree();
private:
	
	//_______Tree data and nodes_________
	class Node
	{
	public:
		string content;
		Node *no;
		Node *yes;
		bool isLeaf;
		
		Node(): no(0), yes(0)
		{}
		Node(string item): content(item), no(0), yes(0)
		{}
	};
	typedef Node *nodePtr;
	nodePtr root, parent, loc;
	//___________________________________
};

main.cpp:

#include <iostream>
#include "tree.h"

int main ()
{
	Tree go;
	char goAgain;
	cout << "loading, please wait..." << endl;
	go.fillTree();
	go.resetLoc();
	cout << "Welcome to Guess The Animal!" << endl;
	cout << "You think of an animal, and I will try to guess it!" << endl;
	do 
	{
		go.play(); // manipulate location from within function before calling again.
		cout << "Play again? (y/n)" << endl;
		cin >> goAgain;
		while (goAgain != 'y' || goAgain != 'Y' || goAgain != 'n' || goAgain != 'N')
		{
			cout << "Please choose 'y' or 'n'" << endl;
			cin >> goAgain;
		}
	} while (goAgain == 'y' || goAgain == 'Y');
	
	go.saveTree();
	
    return 0;
}

any help is appreciated!