While they have no legal standing or constitutional rights to remain within the country, they may stay provided that the government renews their official visas at the expiration of the previous visa.

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As the new century approaches, this has forced many of them to go from expiration after three years to expiration after two. (Visa and Mastercard say they have fixed their own systems, but plenty of sales terminals may still cause trouble.) Meanwhile, Hartford Insurance had to start fixing its systems as far back as 1988, when it realized that its 7-year bonds would crash its software from 1993 onwards.

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The multiple-entry U.S. visa was issued in London, England, in June 2008 with an expiration date of June 2010, Demuren said.

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