Dynamic highlight stopped working

Suddenly dynamic highlight stopped working. If I click to select and there are several possible objects, the popup menu with the possible objects comes up, but when I scroll the list I can’t identify the different ones, they won’t highlight in the model view. If the object has visible isocurves, the isocurves will highlight, but not the rest of the object.

Options>SelectionMenu>DynamicHighlight is checked.

If I start a new model it works.

Any ideas?