Make sure you follow recommended jump start procedure, as there is a risk of dash board damage.
After flat battery may have to leave Ignition switch on for up to 20 minutes before immobilizer will reset. Note immobilizer LED might flash and go out once reset, car should then start.
Intelligent keyless entry system will go to sleep if left for 2 weeks, to save the battery going flat, just press button on remote to wake up car.
Keyless entry, if parked with wheels turned or against kerb etc. You may have to rock steering wheel or turn against load on tyres as engine is started to allow steering lock to disengage.
If in high area of radio interference (ports, supermarket car parks etc.) hold remote key close to Stop/Start button and try to start car, if no luck and you are sure the battery is ok on car (bright headlights) try moving car away from interference.