There is no calibration for the screen. Had a problem with my first droid where the bottom of the screen (portrait mode) was dead. Would not respond to touch along the area where the app drawer icon is.
Had to take it to a verizon store and they gave me a new handset
My daughters Droid had same problem.
We tried rebooting, taking off screen protector, etc. nothing worked.
Took it to Verizon store, they exchanged it for a new one. The good news is that none of your apps, downloads etc are lost, they are all loaded on your new droid.