Here's the problem as I see it. The laminate flooring isn't attached to the subfloor, it just floats to account for expansion and shrinkage due to heat and cold. Therefore, when one nailed the gripper strips it's likely the nails would go through the laminate and secure it to the subfloor. Thus, when the laminate did expand it would buckle causing an uneven place in the carpet. If, by chance, the nails for the gripper strip didn't go sufficiently through the laminate the problem is compounded by not having a secure base from which to stretch the carpet. Usually, if the carpet pad is made from foam material, it's also stapled down, further causing problems with the laminate... in my opinion... but Good luck!