I recently decided to break down and buy some gamebit's so that I can replace my dying cart batteries. I bought a 3.5 mm & 4.8 mm duo off of eBay for $5.00. The baggies they came in said they were manufactured in Taiwan. What I want to know is, is there a good chance I may have ordered some duds? Are foregin gamebits manufactured cheaply, resulting in duds that aren't the correct size?

The first thing I tried to do when I recieved the pair was open up Kirby's Dream Land 2 for the Gameboy with the 3.8 mm. The bit however, didn't seem to catch. If anything, it seems to be stripping the screw. I seem to be putting a lot of pressure on the screw just to try and get it to catch. I shouldn't have to put a lot of force into unscrewing the screw right? I also tried out the 4.5 mm on a Genesis cart but had the same problem. Any words of advise from veteran gamebit users?