Many people are using this add-on. If you're not getting any rates you probably have something misconfigured. Take a look at your logs in the Dashboard for clues as to what might be the cause; you should see some error messages there. Also, make sure the addresses you have entered are correct. UPS does address verification and will not return rates for an invalid address.

Actually, I figured out what I was doing wrong. The products require the weight property be filled in and not zero. When I did this to the products, the problem resolved itself.

My bad. =/

Thanks for the reply and pass it on!!