I keep having problems with nutplates and stop/lock nuts when using screws. They fit the threads so tight that when I try to screw them in the screw heads strip. It doesn't matter whether I hold the screwdriver and turn the nut or vice versa. The result is still the same. The screwdriver seems to fit well too, so I don't think that's it. Any ideas on how to prevent this? It sucks to pay $10 shipping for $3 worth of parts.