In other words, support both "black" and "block", and "white" and "welcome",for at least 3 months, I suggest.
The bug report that introduced this change claimed 100% backward compatability for at least one year, later changed to until 4.0 came out, whenever that will be.
Of course it doesn't actually work that way, as you have observed. But that is just your problem, not SA's, as you can determine from this thread.
Loren
