Very odd......I've tried swapping controls over to the "player 2" side of the A-PAC.......the up and down motions still register just fine, but regardless of whether the brown wire is in the "left" slot and black wire is in the "right" slot, or whether the black wire is in the "left" slot and brown wire is in the "right" slot, the controller doesn't register left or right movements at all. It remains either "fully right" or "fully left", regardless of which direction the yoke is turned.
On the "player 1" side of the A-PAC, the unit fully functions when the brown wire is in the "left" slot and the black wire is in the "right" slot, albeit with x-axis inverted (physically turn the yoke right and it registers as movement left on the PC, physically turn the yoke left and it registers as movement right on the PC). However, when the brown wire is in the "right" slot and the black wire is in the "left" slot, the unit acts hosed again, registering "fully right", regardless of movement. Up and down continues to function properly.