"We knew demand would outstrip supply for some time," says Circuit City's Jim Babb. "I have been told we'll get additional supplies, so I can only advise customers keep checking back with stores and on the website."

Microsoft's Molly O'Donnell says the company has "a weekly replenishment strategy." The first follow-up shipment "is on the way, and it should be on retailers' shelves by the end of the week or for the weekend."

Microsoft won't say how many of the $300-and-up systems were available at launch. American Technology Research analyst P.J. McNealy estimates 300,000 to 400,000 have been sold. The company expects to ship as many as 3 million worldwide within three months; the 360 launches in Europe Friday and Japan Dec. 10. While Microsoft benefits from the buzz created by quick sellouts, McNealy says, "I think they would have been happy to have sold another million if they could have. They just didn't have them."

Meanwhile, Microsoft is acting quickly to address early reports of crashes and glitches. "We are doing everything we can to take care of gamers who are having problems," says O'Donnell, who says the rate of complaints is below the 3% to 5% expected with new electronics products. (Those with problems should call 1-800-4MY-XBOX.)

Online message boards have reflected a number of technical issues, including hardware failure (indicated by three red lights on the power button), freezing games, scratched discs and overheated power supplies. "As soon as the actual gameplay starts, it locks up," says owner Clayton Leasure, 26, of Knoxville, Tenn. He called the support line and was sent a prepaid box to use to ship his console back. "They have been helpful and prompt, so I can't ask for much more," he says.

Not all customers are satisfied. "The level of incompetence I have had to deal with is unbelievable," says Brian Smith, 48, of Owasso, Okla., who is trying to get a new power supply. "I can't describe how disappointed I've been."

Still, Richard Doherty of tech consulting firm Envisioneering Group gives Microsoft an "A" grade for the launch so far. "It could be an A plus if they pull through Christmas with this just being misuse or a misconception," Doherty says. "Do you want to wait six more months for an A plus? Not the gamers I saw in line on Tuesday."