We have six new Nissan Frontiers 3.2 MT 4x4. Three of these have shown a slight pull to the right ("kabig") after travelling over some rough road. We've sent the worst one to the alignment shop twice and there was a slight improvement but the vehicle still pulls to the right. The shop said that everything is aligned and there is nothing more they can do.

Is this common to Frontiers? What can be our next move?