leo72:
I agree with lesto. The infos in that page of the Reference aren't accurate.
PWM frequency is ~490 Hz on pins 5 and 6 (timer 0), and ~976 Hz on pins 9, 10 (timer 1), 11, and 3 (timer 2).
Is exactly the opposite, pins 5-6 @980 Hz, pins 3-9-10-11 @490 Hz 