thanks to Dr. 37 Mike I now have a brand new JIS screwdriver at my fingertips within an arms reach. As you may know it's not just any old phillips screw driver. And as 37 pointed out those cranky derailleur limit screws on all your Japanese derailleurs are JIS so why not use a JIS tool to adjust them. Your phillips is bottoming out and rounding out those screws as we speak.