Nintendo may have a Wii little problem.

The American branch of the Japanese video-game company has sent an e-mail to registered owners of its just-released home console, reminding them to please, please hold on to the Wii's motion-sensitive wireless controller, to always use the safety wrist strap — and to keep their hands dry while playing the physically demanding games.

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"Do not let go of the remote during game play," the e-mail, posted Wednesday on gaming blog Joystiq.com, reads. "For example, in a game like Wii Sports bowling, the ball is thrown by simply releasing the B Button on the remote, not by letting go of the remote!"

"If your hands become moist," the e-mail continues, "stop and dry your hands. Excessive motion may cause you to let go of the remote and may break the wrist strap."

Reuters reported that a Nintendo spokesman had confirmed the authenticity of the e-mail.

"We are investigating" reports of Wii wrist straps breaking, company president Satoru Iwata said Thursday, according to the Associated Press.

"Some people are getting a lot more excited than we'd expected," Iwata said. "We need to better communicate to people how to deal with Wii as a new form of entertainment."

A Web site, http://www.wiihaveaproblem.com, purports to document reports of TV sets, media cabinets, even a PDA screen all cracked by Wii remotes that have flown across rooms and into expensive electronic items.

We at FOX News aren't sure whether to trust photos of TVs that have huge cracks across their screens, yet still seem able to display an image, but others seem genuine.

"We literally have consumers letting go of the remote like you do a bowling ball. You can't do that!" Nintendo of America head Reggie Fils-Aime — dubbed "The Regginator" by wisecracking Nintendo fans for his endearingly aggressive public appearances — told Reuters last week.

The company has not decided on any specific measures to change the strap, Nintendo spokesman Yasuhiro Minagawa said.

Wii owners and prospective buyers can find tips on how to play it safely at http://www.nintendo.com/consumer/wiisafety.jsp.

The Wii, which was released in the U.S. on Nov. 19 and has sold about 600,000 units domestically since, has been praised for the innovation of its gameplay.

Rather than just sitting in front of a TV screen for hours twiddling buttons on a traditional bat-shaped controller, players have to get up and move around in imitation of their game avatars' motions, swinging the bar-shaped Wii remote like a bat during "Wii Baseball" or thrusting it like a sword while playing "Red Steel" or "The Legend of Zelda: Twilight Princess."

For two-handed games, such as "Wii Boxing," users grip a second controller, the "Nunchuk," which plugs into the Wii remote. Perhaps due to its ergonomic design, which fits neatly into a cupped hand, there have been few reports of wayward Nunchuks.

In fact, neither controller has to go airborne for there to be collateral damage during Wii play. Some of the photos on wiihaveaproblem.com show household items destroyed by flailing flesh-and-blood arms.

"Allow adequate room around you during game play," advises the Nintendo cautionary e-mail. "Stay at least three (3) feet away from the television. Make sure objects and other people are out of your range of movement."

Reviewers have complained of sore shoulders and aching elbows after playing the games for hours — but all agree that Nintendo's got a winner on its hands with the Wii, which costs half as much as the higher-powered, more traditional Sony (SNE) PlayStation 3 and Microsoft (MSFT) Xbox 360, but seems to deliver twice as much fun.

Nintendo has delivered more Wiis so far to consumers than Sony has of the PlayStation 3, partly because of Sony's production problems.

Nintendo has shipped about 400,000 Wii machines in Japan and more than 600,000 in North America. The machine went on sale Thursday in Australia and is set to go on sale Friday in Europe.

Sony readied just 100,000 PlayStation 3 machines for the Japan launch, and 400,000 consoles for its U.S. debut on Nov. 17, two days before the Wii went on sale. Its European launch has been pushed back until March.

Sony has promised 2 million PS3 machines by the end of the year, while Nintendo is targeting 4 million in global shipments of Wii during the same period.

Both Sony and Nintendo are projecting selling 6 million by the end of March.

Iwata denied that Nintendo was competing against Sony. It's more important to attract novice players and to reach out to older people and others usually not associated with games, he said.

Analysts say Wii appeals to inexperienced players and has a price advantage at 25,000 yen or $250 — about half of what the PlayStation 3 costs.

Even the backlash against the Wii hype, such as it is, has been good-natured. The operators of wiihaveaproblem.com freely admit to owning the console — "because we're fanboys, that's why."

FOXNews.com's Paul Wagenseil and the Associated Press contributed to this report.