this is why we were taught to turn the screw backwards until it dropped into the existing thread . you can feel it . some of our newer techs havent been taught this and i come across so many threaded screw holes, only thing to do is use a bigger screw..lolReminds me. I have a device with a transparent case, and messed up the look of it a bit by not being careful enough screwing it back together, and gouging out a new thread path on the plastic. It now looks a bit uneven and opaque there instead of the clear crystal it was before.