Inconsistent results with associative unfold

I've been experimenting with associative unfold, a new feature in V19, which supposedly allows you to make a change to an unfolded blank, which will then be reflected back to the folded part. Yes, there are some cases when you might want to modify a blank and see how it affects the folded model.

I am getting very inconsistent results. Often, I am told the changes propagated successfully to the source model, but they don't appear. This is not a matter of doing a refresh or regen operation. What is even wierder, is sometimes in cutting a small hole, I lose flanges from the folded model, or the ENTIRE folded model disappears. Sometimes the folded model assumes the color of the object that was subtracted from the unfolded model.

I opened a SR on this, and Illya has not been able to replicate the problem. . But I was wondering if anyone else was having problems with the tool....