Like I've said before, It's either fuel or spark. If you're getting fuel, then it has to be spart. Don't base things on "This is only a year old, that is only two years old, etc". An electrical part can be bad right out of the box, or fail any minute after it's installed. You've obviously got an electrical part that is breaking down when it gets hot. That's why it quit and wouldn't start. That's also why it started once it cooled down. This type of problem can be intermittant, and happen at different times. Key candidates would be coil, ballast resister, or ignition box.