I would be willing to bet $$ on the FPR. For $15 and 5 minutes work, replace the fuel pressure regulator. It is leaking, causing a "flooded" condition immediately after shutting down, making hot starts next to impossible. Cold it starts as the fuel has had time to evaporate. I had this symptom about 2 years ago, fixed it myself its right under the plastic engine cover.
Don't bother checking the fuel pressure, it wont show the slight leak in the regulator. Everything will appear fine. Call a Pontiac dealer and ask for a tech or service mngr, that is what I did, I replaced the regulator and he was right, it fixed the problem...
I've also done the Crank sensor, the car was cutting off when running here and there. Much more time consuming and not at all likely the culprit.