symbology inverted

I am working with points symbolized as a "target" over a colored circle. When I last worked with the mxd (a couple months ago), all was well. Today, I am changing the symbolization to add a third layer, a white circle behind the target and colored circle. Suddenly, the colored circle displays - incorrectly - on top of the target, yet it is correct in the Symbol Property Editor and in the legend. I tried a workaround by switching the layers in the Symbol Property Editor, but then, I have to do a workaround for the legend also.

Any ideas as to what is going on here and how to fix it would be welcomed.

Teri