I ran into the same problem recently where the staples for saddle stitch came out on the front of the spine. Service lead me to some NVM values you can change where the staple position sets and it is adjustable for different sized booklets (amount of actual pages) and it worked very nicely. Good luck.
I'm running a 700i with a Fiery controller. Is there a way to adjust the staple and fold position on a saddle-stitched booklet from within the Fiery controller? I see where the adjustment is at the engine when you make copies, but adjusting it there doesn't change the position when you send a job from the Fiery.