Hacking Replacement DS phat screen stopped working - why? and can I get an off

[SG]

OK, got a new screen for the wife's DS phat. She bought it off someone cheap but the screen was horrifically gouged by a casual n00b.

So, I ordered a screen form Deal Extreme. 1/3 the thickness of the original! Worked OK for about a week (but it did lack the sensitivity of the original - run the stylus across and sometimes you get a gap in a line the chatbox) but the the touch responsiveness just completely stopped.

So I'm wondering if anyone knows where I can get an original Nintendo manufactured screen or why it's behaving this way?