What could be causing my (non-)starting issues? Occasionally (once every two weeks or so) when the keys are inserted and turned to the start position, nothing happens. No noise, no dome lights dimming if they're already on, nothing. The dash lights come on, as well as any accessories (radio, blower, etc.), but nothing to indicate that it's trying to start. Sometimes I can just take the keys out, put them back in, and then it starts normally, but sometimes it will take several minutes of trying before The starter actually engages and then the engine will start right up (no whining or sputtering, just a normal start).
The battery is less than a year old. The van has about 90k miles.
It's unlike any electrical problem I've had other vehicles (alternator/battery/solenoid/starter issues) -- in those the car would either try and fail to start or wouldn't start at all because it was totally drained of battery power.