Lights flicker at high rpms.

I was drivving my eclipse last night and i noticed that at high rpms (like 5500) all my lights flicker (headlights, gauges, etc.) I know the alternator is good because it's almost brand new and i'd expect problems at lower rpms. I tested the battery with the car running and it was 14.4v. Anyone have any suggestions. BTW the engine doesn't stumble so i don't think its affecting ignition.