Sounds like the battery to me. Is it the original battery? You can not tell a thing by the lights operating. It could also be the starter, but my money is on the battery.
I think the key symbol is the immobilizer. It should go out with the key in the ignition. If it isn't going out, and the car won't start, you may need to have the key reprogrammed. A weak battery could activiate the immobilizer as well.
Last edited by AHan; 05-12-2011 at 02:00 PM.