g++ 4.6.3 on Ubuntu 12.04 fails to open any fstream file

If one declares a fstream class the file will never be opened.
A simple file to illustrate the bug is listed below.

#include <iostream>
#include <fstream> // std::ofstream
#include <iomanip>
#include <string>
using namespace std;

int main () {

    fstream outfile;
    outfile.open ("test.txt");
    if (outfile.is_open()) {
        outfile.write ("This is an apple",16);
        string t;
        outfile >> t;
        cerr << t << endl;
        long pos = outfile.tellp();
        outfile.seekp (pos-7);
        outfile.write (" sam",4);
        string s;
        outfile.seekg(0);
        outfile >> s;
        cerr << s << endl;
    }else{
        cerr << "error opening file tst.txt!\n";
    }

    outfile.close();

    return 0;
}

g++ --version command yields:
patrick@bucephalus:~/test$ g++ --version
g++ (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3

Thank you!