FARGO - Service is up and running for Verizon wireless customers in the region who heard more busy signals than dial tones this morning, Verizon officials said. The Verizon network team discovered an issue about 10 a.m. that needed to be immediately addressed, said Karen Smith, Verizons public relations coordinator. The problem was fixed about noon. Smith said the situation was unusual. Its very rare that this happens when it would affect all customers in a network, she said. Smith would not disclose the nature of the maintenance issue. Affected networks included Fargo, Moorhead, Grand Forks, N.D., and Duluth, Minn. Maintenance issues typically take about thirty minutes to fix, and are usually taken care of in the middle of the night when most customers are sleeping, Smith said. We really do apologize to our customers for this, she said. We understand its an inconvenience. Verizon is touted as being Americas most reliable wireless network, according to their Web site.