take a small file or dremel and cut a straight cut into the screw then use a straight blade screw driver. go slow with the extraction. the power driver isn't always a good tool
Busted Phillips Screws
one of the lugs on my speakers came loose , so I used a power screw driver to remove the Phillips screws holding the plate in the back. 3 out of the six screws came out fine. The other three had the indentaions smashed, now I am stuck with three phillips screws that I can get out. Will seek the advice of someone more mechanically inclined then myself, but any advice is appreciated. My thought is to take a drill and destroy the screws completely. However I wont do anything until I consult with a few friends. THX