wtf? - fstream

let's say i have a couple of functions

void f1(fstream& file, string filename);
void f2(const string data, int& start, int& end, fstream& file);

when i run f1 i get the following output:
2               (wrong)
80              (right)
2               (wrong)


f1(fstream& file, string data)
{
    int start, end;
    file.seekg(ios::end);
    cout << file.tellg() << endl;

    f2(data, start, end, file);

    file.clear();
    file.seekg(ios::end);
    cout << file.tellg() << endl;
}

f2(sting data, int start, int end, fstream& file)
{
    file.clear();
    file.seekg(0, ios::end);
    int FileSize = file.tellg();
    cout << FileSize << endl;
}

wtf?
shouldn't it produce:
80
80
80

stdio