Ordinate Dimensions to Midpoints Not Updating

Here's the situation:

I make a model.

I make a drawing from the model.

I dimension the drawing with ordinate dimensions.

When I change dimensions in the model, if they are rectangular, dimensioned to a midpoint on the drawing, they don't update.

Why might that be?

Have SW 2013

Win 7 (curse it!!)

SolidworksDrawings And Detailing