It sounds like the sensor wire isn't getting seated properly but the speed control might have some other problem.

I'd check the sensor plug and make sure that it's seated all the way and correctly (I've seen a couple get shoved in backwards).

If that doesn't fix it, drop the Novak guys an email and they can help you out. Normally they get back to you within a day as long as there isn't a big race going on.

Novak has some of the best service in the industry so they'll get you going quickly.