Nike plus (+) - calibrates walk only

I upgraded from an ipod nano to an iphone 4, using nike plus. On my ipod, i could calibrate my sensor to running and walking by entering a distance, and then traveling that distance.

With iOS4, I can only calibrate by traveling a distance, and then selecting the distance i traveled. The trouble is, the distance I am allowed to select is limited. When I run 2 miles and attempt to calibrate, the maximum distance it lets me select is 1.2 miles. When i run 3, the max is 2.4. Additionally, it then calibrates that as a walk, even though it has my pace nearly right at 8 min/mile.

I do the calibration on a treadmill, so it is very accurate. Also, it is not the sensor, as i had calibration working perfectly on my ipod nano.

How can I both:
(1) force calibrate run
(2) force the distance i actually traveled

Thanks.