My ssf4 fightpad i think is starting to be pretty hit and miss with registering diagnols. Ive seen people place some cardboard or tape or whatever underneath the plastic of the d pad. I guess i wanna know how effective that has been for people when it comes to the dpad responsiveness.
I say first before you try to mod the fight pad, open up the pad and clean the contacts on the d-pad with some q-tips and rubbing alcohol.
Then put your pad together and see if it changes anything.
open it up and check the rubber part under the d-pad, make sure its not torn.