Country Time Eliminate

I have all my contacts in Microsoft Outlook 2007. Every so often, the program seems to undergo a patriotic surge and it adds "United States of America" to the address of every contact listing. This includes contacts that are not in the U.S. if I have no address specified. For instance, I have about fifty listings which feature a foreign person's name plus either their phone number or the e-mail address. But all fifty or so of them now have "United States of America" in their mailing or street address field, which I'd left blank. Anyone have an idea how to fix this?