Give it time. If you still have the old URL as well, make it redirect to your new one. Google will catch on eventually, especially if you have updated dmoz. Another trick is to search for your page, then click the 'dissatisfied with your results?' link at the bottom, and say that you have a new page and give the URL.
You think Google is bad at this, try MSN search

I changed the URL of my personal page last year, and the old URL has long expired. MSN *still* points to that page as its number 1 result, despite it just showing a no-server error now.