One problem related to ignition switch has been reported for the 2009 Nissan Altima Hybrid. The most recently reported issues are listed below.
My car was parked and off, and had been working fine when I parked it about 8 hours earlier. It was parked indoors in a garage on a warm fall day, so extreme temperatures and weather were not present. The parking spot and location were unremarkable (I was parked at work, which is safe and no one would have tampered with the car). After 7 years with no problem with the push button ignition switch, it suddenly refused to acknowledge the remote key fob. They key continued to work with the doors and trunk, and the car battery was fine. It would not accept the key when placed into the emergency ignition slot, either. The dealer determined that the lock steering unit needed to be replaced for a parts cost of $678 and labor of $303. I looked online, and found that there are many other Nissan owners with cars made around this time frame with identical issue and fix. It sounds like a serial defect to me, and I believe Nissan should bear the cost.