Quoted from pinnyheadhead:2 of my opto wires were switched around incorrectly on the board and that solved my issue. So check that first. I wish it was that easy for everyone.
I'm thinking this may be my problem (during Vengeance multi-ball, if I hit the second ball into the lock, both it and the first ball stay locked until it times out). How did you know the optos were reversed? What should I look for? Thanks!