STL container relocated in memory!? (shifting sands)

Hello -

To begin with, I'm not the most experienced STL use out there but I'm
slowly getting there. One bug(?) that's plagued me of recent is the
way the OS (or is it STL?) appears to relocate a container in memory
if for example the container needs to grow, with the result that any
references (iterators included) to items in such a container cease to
be valid and may return the address 0xCDCDCD or 0xDDDDDD in the
windows environment (I now know what these pointers mean). I haven't
read the standard but I'm guessing it there's something about elements
of some(?) containers needing to be stored contiguously in memory, and
as such the runtime(?) may relocate a container to guarantee this. Is
this so?

Also, lately, its happened that while in the middle of a series of
function calls that do nothing to alter (i.e. grow) the container, an
existing iterator to the container ceases to be valid, apparently the
container has been moved, or so it seems.

Here's a small example I just cooked up:

#include <iostream>
#include <vector>

using namespace std;

int main(int argc, char* argv[])
{
    vector<int > test;

    for( unsigned i = 1; i < 10; i++ )
    {
        test.push_back(i); cout << "pointer: " << &test.front() << endl;
    }
    return 0;
}

Output:
pointer: 00335448
pointer: 00335570 // changed
pointer: 00335670
pointer: 00335570
pointer: 00335670
pointer: 00335670
pointer: 003356B8 // changed
pointer: 003356B8
pointer: 003356B8

Oddly, lists are not so affected i.e. when I change the type of test
to list<int > , the problem no longer happens:

pointer: 00335488
pointer: 00335488
pointer: 00335488
pointer: 00335488
pointer: 00335488
pointer: 00335488
pointer: 00335488
pointer: 00335488
pointer: 00335488

I guess I've partly figured out the problem, but I'd appreciate more
insight on this problem/feature.

Thanks,

- Olumide