Just did this http://www.ufighterx.com/guides/videogame/360dpadfix/360dpadfix.htm It's real simple and it's a hell of lot more responsive now.
I was about to take one of my wireless controllers apart to see what the problem was, I thought it was just a dirty response pad, but I'll have to pay more attention now. Oddly enough, I bought a black wireless controller, and the D-pad works fine. Since I'd been using that one lately, I almost forgot about the white one...
Just get yourself this handy-dandy controller... I actually bought one of these, they're surprisingly cool...
