What Targom and Foncy said are both true. There was a bug with the current release of SimC. If you want to pick up the latest build, that has the fix, you would need to download the nightly build which you can find here:
http://downloads.simulationcraft.org/?C=M;O=D
As for ChiX, ChiX is not THAT great in pure single target. It takes 2-3+ targets to where it would start to become a gain over Serenity. It TRIES to use ChiX at 3 chi but it will use it at 4 chi if a few scenarios are in effect (such as CB:TP being up at the same time)