Can anyone explain to me why the D2X has the aperture limitation based on ISO when using flash? I'd like to understand why I can only open to f4 when at iso 100. Oddly enough, the camera will still fire at wider apertures, but the pictures have a bluish cast and require color correction. Why is this limitation there? Why does the camera even fire at apertures it does not support with flash? You guessed right, I took some flash portraits yesterday at f2.8 before I realized my blunder.