IP Address issue with HBO Now

According to the folks at HBO Now, my IP address is showing up as being outside the US. Here is part of the email that was send to to me after I contacted them:

"After researching your account, it appears that our systems are having trouble determining your location. This usually happens when your IP address shows as being located outside the United States. Normally, restarting your modem & router, as you have done, should resolve the issue. Since it has not, we recommend that you contact your internet provider to advise them that your IP address needs to be corrected."

Can this be fixed or do I give up on the idea of using HBO Now.