Cox Communications Inc. said yesterday that some of its Northern Virginia customers were unable to access the Internet after June 22, when the company began upgrading its high-speed service.
Customers using Toshiba PCX 1000 or Toshiba PCX 1100 cable modems have the problems. The upgrade raised connection speeds for customers with two of the three Internet packages that Cox offers, and those modems are not compatible with the higher speeds.
The company, which has 2.7 million high-speed Internet customers nationwide, sent notification letters only to customers who paid for the priciest and fastest package. Those who paid for the second-fastest Internet speed -- more than 80 percent of the company's subscribers -- were not warned because their service was less likely to be interrupted, the company said.
"We decided that we felt that the majority of those customers would be fine no matter what modem they have," said Alex Horwitz, a spokesman for Cox in Northern Virginia.
That left Northern Virginia customers such as Mitch Schlesinger without Internet service for almost a week. The Fairfax County resident said he started noticing problems with his Internet connection right after he received an e-mail from Cox advertising the upgrade.
"The Internet connection slowed to a crawl, what I would term slower than a 56K dial-up speed," said Schlesinger, 38, who works at an investment management firm. About five days ago, he couldn't reach the Internet at all.
Cox estimates that about 1 percent of its high-speed Internet customers in Northern Virginia could not connect to the Internet after the upgrade. It would not say exactly how many customers were affected, citing competitive reasons.
The company mailed about 600 letters to customers with the Toshiba modems who subscribed to the fastest Internet option, which costs $70 a month, or $55 with cable television.
The option now provides an Internet speed of 15 megabits per second for downloads and two megabits for uploads, about three times the speed before the upgrade. The second-level option costs $55, or $40 with cable, and has speeds of five megabits download, two megabits upload. Not all customers who had Toshiba modems and used the second option were affected.
Cox said it didn't want to alarm all customers using the second-fastest option by sending them letters. The company planned to deal with those who had problems case by case, Horwitz said.
"We didn't want to be proactive and have customers call us worried that the service would go out," he said.
He said that customers who rent the Toshiba modems from Cox and cannot access the Internet after the upgrade can go to the Cox retail stores in Kingstowne or Herndon to trade for compatible modems, without charge. They can also call Cox's customer service department to have new modems installed, also free.
Schlesinger said he called Cox and will receive a rebate for the week he had no Internet access. He said he had Internet service yesterday morning, but that he does not know if the problem has been permanently fixed.
Cox used to lease out both of the Toshiba modems that now may be incompatible with the new Internet speeds, but stopped offering them in April to customers subscribing to its more expensive packages.
Until a few weeks ago, the modems were still available for customers paying for Cox's slowest Internet option, which costs $25 a month. Those customers are not affected by the upgrade, the company said.