Motor Voter

When I changed my driver's license and car registration from New York to New Jersey a few months ago one of the forms had a box to check if you also wanted to register to vote in New Jersey.  I checked the box and was impressed with how simple this was.  Too simple as it turned out as subsequent checks showed I was not in fact registered to vote.  My best guess is a clerk was suppose to notice the box was checked and give me a registration form.  Not a big deal as I found a form on the internet which I filled out and mailed in and I recently received a post card confirming that I am now registered.  However this kind of defeats the purpose of motor voter laws.