Icons don't update when default program changed

Suppose I have a file type (such as .cpp or .vhd) that is opened by

program X by default. Then I change the default program to Y by

selecting "Open With...", choosing a new program, and checking "Always

use this program". Whenever I do this, I've noticed that the icon for

files of that type does not update to Y, but instead stays with X's

icon. Is there a way to "refresh" the system so that it associates

the correct icons with file types?

-J