If you've got an early Apple iPad, chances are its screen was cleaned with a banned substance called n-hexane, which releases a toxic nerve gas upon use. In January, 2,000 workers at Wintek's East China LCD plant went on strike, claiming the substance was poisoning them, and now 44 of those reportedly affected are planning to sue. According to reports, the screen cleaner was originally used because it performed better than alcohol, but Wintek has since fired the factory manager who suggested n-hexane and discontinued its use. That didn't keep 62 workers from winding up i