The first major business day of the millennium opened with few signs of Y2K computer glitches, much to the delight of stock markets worldwide. At least two stock indexes hit new heights.

Those returning to work today found energy supplies and corporate computer systems operating smoothly. The U.S. banking system was "running smoothly" this morning, said the U.S. Federal Reserve. Bruce McConnell, director of the International Y2K Cooperation Center, told the CBS "Early Show" that nothing serious was reported anywhere and "the risk is very low at this point."Not that the Y2K bug was nowhere to be seen: Glitches hit government computers in Hong Kong and mainland China. Police testing the sobriety of drivers in Hong Kong had to enter birth dates on breath-testing machine because of an apparent Y2K malfunction. Courthouse computers in Italy mixed up prisoner dates by 100 years. A few ATM machines shut down.

But there were no reports of calamitous failures some feared -- and stock markets responded.

U.S. markets followed the rest of the world with a smooth start to the first trading day of 2000. But an early rally in the Dow Jones industrial average and Nasdaq composite index evaporated on interest rate worries.

Stock indexes in Hong Kong and Singapore, both of which rang out 1999 at record levels, soared again today. Singapore's main index closed 4.2 percent higher, and Hong Kong shares rose 2.4 percent.

Pakistan, one of the countries experts were most worried about, opened its stock market with success, as did India. In Germany, the index of the top 30 stocks hit a record high in the first hour before ending the day down 3 percent.

Finland, Denmark, Sweden and Poland reported no Y2K problems, as did the Chicago Mercantile Exchange and the Chicago Board of Trade. Markets in Japan, China, Switzerland and London were closed Monday, but Britain's Cabinet Office reported business as usual and Swiss banks noted no signs of abnormalities.

The French Ministry of Finance announced: "Today, there has been no bug, which is to say that all the great computer and electrical systems around the world successfully passed in the year 2000."

The Y2K bug can affect older computers that read dates only by the last two digits of the year, and can malfunction if they misinterpret 00 as 1900 rather than 2000. Few problems were reported during the millennium rollover at midnight Friday, and experts then turned their attention to today's opening of the financial markets and first business day.

"We're seeing that there were no threatening effects in the companies," Salvador Bellido, vice president of the Spanish Confederation of Medium and Small Businesses, told the private news agency Europa Press. "We think the media pressure worldwide has been excessive. We're beginning to think that all this has been set up for someone's benefit, I don't know if it was Bill Gates or who."

Companies and governments around the world who had set up Y2K response teams began disbanding operations and sending workers home.

But officials gave the same warnings that moviegoers shout near the end of a horror film: The threat's not over yet.

"There'll be a lot more systems brought into play and the likelihood of Y2K events are certainly much greater than they've been," said Sen. Ian Campbell, in charge of Australia's Y2K watch.

The few problems caused by the millennial bug were more a nuisance than a catastrophe.

The Y2K bug infested a computer at Oak Ridge National Laboratory's Y-12 nuclear weapons plant in Tennessee but it did not affect operations or workers and was fixed three hours later. Computers at courthouses in Naples and Venice in Italy listed prisoners due to be released Jan. 10 as having completed their terms Jan. 10, 1900.

Government computers in Hong Kong failed to display the correct date, but no records were lost and everything ran smoothly, officials said. Weather observations in part of mainland China had to be made by hand after the circuit board of a solar measuring device in the remote northwestern region of Ningxia failed to roll over to 2000.

In Tokyo, about a dozen small brokerages reported Y2K-related glitches in a record-keeping system. They were quickly fixed. Ten small Hong Kong companies reported minor hardware or software problems possibly caused by Y2K. The heat went out in apartments for about 900 families in Pyongchon, South Korea.

A novelist in China who wrote stories about the millennium bug lost much of his work when the rollover to 2000 crashed his personal computer, destroying all his files. Luckily, Gu Qingsheng had already sent a completed manuscript of his latest novel to his publisher.

A hospital in western Norway reported that an X-ray machine had failed. News reports said cash registers at a handful of 7-Eleven convenience stores also failed there, and some ATM machines weren't working.

There were no Y2K problems at Ohno-ya, a shop specializing in traditional handmade stationery located across from the national Kabuki theater in downtown Tokyo.

Shopkeeper Hiromitsu Yoshino's bookkeeping method is 100 percent Y2K-compliant. "I use an abacus," he said.