I bought the arcade sticks and did the same as you. I put resistors on the triggers to neutralise them and wired them up to my terminal block, bringing the total number of available buttons to 12. At the moment, only 8 of them are in use (9 if you include the Xbox guide button) but the others are wired up for future expansion. It's a great board to solder, most of the points being large and pre-drilled.
Just found the problem with not adding the resistors

Any chance of a picture of your wiring mate?