As the world returns to work in a new millennium, the computer bug which apparently threatened chaos has caused barely any damage.

The Y2K bug has been squashed

US Y2K trouble-shooter John Koskinen

But a top Slovenian Y2K official has now lost his job after accusations that he had exaggerated the dangers. And in the US, there are unconfirmed reports of threatened legal action over the money wasted in busting the bug that did not bite.

So, was the estimated $500bn spent world-wide fighting the millennium bug really a waste of money?

The generally seamless global transition from the old millennium to the new does suggest that the lavish preparations were over the top.

The Brazilian stock market traded unaffected

As does the impression that countries whose governments spent very little on tackling the Y2K bug, like Italy and Korea, fared just as well as those who spent a lot, like the UK and the US.

But two facts suggest that a large part of the expenditure was money well spent. Firstly, there were actually plenty of Y2K problems.

They did not involve nuclear missiles accidentally launching or stock markets crashing into techno-meltdown, but they were genuine Y2K problems nonetheless. The millennium bug was real.

Some verged on the serious, like the glitches that hit the Japanese nuclear power plants and the US military satellite.

The Y2K bug was very real and if we didn't prepare there would have been a heavy price to pay

US Energy Secretary Bill Richardson

But most were mundane, from broken bus ticket machines in Tasmania to police breath-testing equipment in Hong Kong. Hundreds of document printers and websites also failed to cope with the rollover, with the year 2000 being rendered variously as 100, 1900, 3900, 19100 and 192000.

The fact that none of the glitches caused major incidents is widely seen as vindication of the Y2K preparation.

The Y2K bug added 100 years to some prison sentences in Italy

Bruce McConnell, Director of the UN-backed International Y2K Co-operation Centre said: "Without this work, serious disruptions would have occurred."

The second fact which may in time indicate that the Y2K money was well spent is that the Y2K bug is not dead yet. The true extent of the Y2K bug is yet to be determined and may turn out to be much larger than is now obvious.

Most estimates suggest that problems will continue to crop up for several months, if not the whole year.

"We are likely to continue to see glitches pop up here and there in the coming days and weeks," said US Y2K trouble-shooter, John Koskinen. "But I think they will not pose a threat to the nation's economy."

Robin Guernier, head of the UK's independent bug watchdog Taskforce 2000, agreed: "We have a long way to go, the whole of 2000 and into 2001. It's really far too early to breathe a sigh of relief and say it's all done."

Y2K errors

US - $91,250 fine charged for video 100 years overdue Denmark - First baby born registered as 100 years old at birth Germany - Man reported to have over $6m credited to his bank account on 30 December 1899 Cuba - Newspaper suggests Y2K bug was a capitalist-hatched plot Thailand - Street vendor anxious about Y2K withdraws life savings which are then burnt in a house fire

A further factor potentially underplaying the extent of the Y2K bug is the reticence of organisations to report problems - it simply does not look good, as Telecom Italia found when it sent out bills dated 1900.

Economic boost

The extraordinary sums spent on tackling the Y2K bug may even bring benefits to businesses and national economies, believe some analysts. This is because older computer systems cobbled together over years were swept away by new, fast and streamlined networks.

US economist Lawrence Kudlow, at Schroder and Co investment bank, said: "Y2K turns out to be a large net plus for the US economy."

British Energy spokesman Bob Fenton agrees: "We've had an opportunity to dump a lot of redundant software."

The French telecommunications company Cegetel also had no regrets over spending $33m to prepare for the year 2000. "The money we spent will be recouped in the long term because we now have an excellent, modern network. That can only be positive," said Cegetel spokeswoman Valerie Piot.

Those who were charged with tackling the millennium bug would have been damned if there had been major problems and are now being damned because there were not.