I just wanted to share that I was also having trouble using this feature.
The message I've gotten is: "Could not determine latitude and logitude for specified address.".
I have tried a number of entries, but only one browser on one machine (Chrome Version 26.0.1410.43 m [up to date as of this moment] on Windows 7, 32-bit).
Entries I have tried include all arrangements of:
City: [Blank], Montclair
State/Province: [Blank], NJ, New Jersey
Zip / Postal Code: [Blank], 07042
Country: [Blank], USA, United States, Unites States of America
Within: 20, 50
All variations yielded the same error message.