Hacking Touch Screen Funny

[mayfly]

I recently found my old DS phat. But the touch screen is now dodgy. One half (the right) worked fine, while when you hit the middle it jumps so that the touch screen is to the left of your stylus. I did about 30mins of calibrating and now its the otherway round! Anyone know if this is fixable? Maybe a proper reset of teh DS back to factory settings?

Cheers