I have enabled the feature freeze in options, but the yellow/gold bar is not at the top of my tree.  I am able to right click on a feature and there is a "freeze" selection, but in picking it nothing appears to happen.  This isa large tree with multi bodies.

I experimented with the freeze early on, but have not used it much, it seemed that 2012 had gotten much better in general with the uncesscesary full rebuilds happening when you would not expect them to.

Any things to look for?  Or reasons when freeze is not applicable?