a couple of amateur thoughts on this...
my '02 car originally came w/ a temperature sensor that wouldn't allow the top to go down below 28 degrees. of course, it wouldn't allow it to go up either. so it got stuck down one winter morning when the temperature plummeted and the car had been sitting in the garage over the weekend.
took it straight to the dealer, where they removed (maybe bypassed) the sensor. those sensors are no longer used and the top works great.
also - since new, i've had the recurring problem of either the top not operating from the interior button - or not from the driver's door lock. if one doesn't work, the other will. being that it's an intermitent problem and that it doesn't register in the car's tracking computer, there's nothing that can be done. fine, because at least one way always works.
if you're lucky, it might be one of these two problems.