PyNew_Interpreter(): "Fatal Python error, invalid thread state for this thread" question

Hi,

Trying to grasp Py_NewInterpreter()in a simple app embedding Python, I was
wondering why the following gives me an error:

int main() {

PyThreadState *tstate;

Py_Initialize();
//The following returns
//Fatal Python error, invalid thread state for this thread
tstate = Py_NewInterpreter();

//etc..

Python is 2.3.3c1 on Win XP
Pointers much appreciated

Regards

Vincent Wehren