Many home centers sell a liquid screw 'fixer' just for this problem. Put a drop in the screw head, wait a few minutes, press the driver into the head and remove, wait another few minutes for it to completely harden, the remove as normal. Otherwise, you may have to drill and use a screw extractor (also sold at home centers) to remove it. It's a problem, but not unsolvable.
Stitchawl