Clogged winshield vent??

[gary at squirrelsoup.net]

I was driving in the bitter cold last night (go boston).

If you can imagine the winshield heater vent like this

| | | | | | | | | | | | |

It seems that the middle 3 have no air coming out of them, and i get a
nice pattern of ice on my windshield.

----------------------
       \------/
        \----/
         \--/
          \/

----------------------

(V pattern in middle is ice)

Are there any known problems like these?

-Gary