Well, I just fixed mine and it works great now. If you have a set of precision screwdrivers, some tape, and you are good enough at disassembling things and putting them back together carefully, then give this mod a shot:
And here's a few additional tips:
When you get down to the last 4 screws that access all the face buttons and D-pad, be especially careful to keep all the buttons in place into the controller shell/casing. Tape no more than a 3rd of the circular contacts (I used electrical tape). When reassembling, after reinserting the last 4 screws (now first 4) test all the buttons and ensure that they feel right and that none of them are getting stuck. Once they seem to be working correctly, then continue reassembling until you get to the battery. At this point, you can test the D-pad on a game to ensure that you like the results. I found Dark Souls to be a good game to test on, since the D-pad equipment UI flashes when each button/direction has contact. If it's all good, then continue to reassemble the controller.