A New Jersey consultant waited a week to send crucial business e-mails as Comcast Corp. encountered problems switching customers from the cable Internet service run by bankrupt ExciteAtHome to its own new network.

Another man got so frustrated trying to call Comcast's customer service lines he gave up.

"They have about four different numbers and you're stuck on hold for half an hour, three-fourths of an hour. Finally I went and I hooked up to AOL," said Stanley Baran of Wallington, N.J.

The consultant, Ken D. Balick of Montclair, N.J., was hurrying Friday to send e-mails to plan an upcoming trip to Japan and Korea. His Internet connection was working after a Comcast representative visited his home.

"It should not take seven days to get a service representative out," he said.

Comcast said it had largely solved problems customers have complained about as it has switched the first 300,000 of its ComcastAtHome subscribers to its new Comcast High Speed Internet service.

Dave Watson, executive vice president of Comcast Cable, acknowledged "some early issues in a couple of the markets." But Watson said, "I think we are making very good progress."

Comcast had known the changeover was imminent since a bankruptcy judge in California ruled that ExciteAtHome could shut down its system on Nov. 30. Comcast subsequently agreed to pay $160 million to keep the Excite service running through Feb. 28.

But Watson said the company expects to switch all of its more than 800,000 high-speed Internet customers over to its own Comcast High Speed Internet service by the first week in February.

Watson said Comcast has encountered some problems, but that the company has worked them out. He wouldn't reveal how many customer service representatives Comcast has fielding calls about the changeover.

"We added additional staff," he said. "We spent several months training people prior to this."

Jeff Kagan, an independent telecommunications analyst in Atlanta, said preparing for the switch "would be like Atlanta preparing for a major snowstorm: it's not going to happen very often and it's very difficult to prepare for."

"When it happens you just run 24 hours a day and try to get the problem taken care of with the least amount of hassle for your customers," Kagan said. "Customers who use this technology just have to realize that they are on the bleeding edge and this is why they call it the bleeding edge. It'll be rough for a few weeks and then it will be a memory."

But some customers said their problems were severe, and Comcast should have been better prepared.

"They just weren't equipped with the manpower and technical expertise to have a seamless transition," said Balick, who said the high-speed connection is crucial for his consulting business, which advises companies on global expansion plans.

"I'm sending hundred-page PowerPoint presentations to presidents of Asian corporations on behalf of my clients," he said. "You can't send a PowerPoint presentation with graphics through a dial-up service. There's not enough bandwidth. It's not an option."

In the Detroit area, Leslie Helwig, cable director for Bloomfield Township, said she has heard from dozens of complaining Comcast customers.

Comcast has about 16,000 subscribers in Bloomfield Township and the Bloomfield Hills community, including about 3,000 Internet customers. It is the area's only cable provider, "and that makes it frustrating for consumers," Helwig said.

"Comcast should have seen this coming," said David Butler, a spokesman for the nonprofit advocacy group Consumers Union. "If the marketplace were more competitive, we believe Comcast would have done a better job of serving their customers and helping them through the transition."

Comcast has said it will give refunds on a case-by-case basis to customers who call to report that they were out of service.

Comcast's Watson predicted that in the long run, customers will like the new service, which he said offers features — including ability to access e-mail from any computer and additional storage for music or picture files — that the AtHome service did not.