If it is a case of the LPR being set too high, do the following to reset it to the stock value:
1) Screw the cap out the front of the LPR underneath the breach using a 1/4" allen key
2) Whip out your 3/16" allen key, put it into the bronze seal assembly (centre of the pic below) and turn this down (clockwise, as arrow indicates) until it is reasonably tight (but not too tight, so you don't damage the seal):
http://img354.imageshack.us/img354/2776/lprcd1.jpg
3) Once it's turned down fully, back it out (anti-clockwise) 5 complete turns and test it again (as it is now at the default value). If you still chop, try turning it clockwise 1 complete turn and retry. If the chopping doesn't go away, it could be an internal problem with the LPR or the paint.
-Will