The millennium bug has hit a decade late as businesses struggle with software that cannot handle the changeover to 1 January 2010.
The original Y2K bug affected computers on the switch to the new millennium on 31 December 1999, because the dates encoded into old software only used two digits rather than four.
Users on security bulletin boards complained that Symantec SpamAssassain incorrectly scored legitimate e-mail as spam because the software thought that the date the message was sent was in the future, due to the date bug.
Dow Jones reported that 30 million German bank cards at Deutsche Sparkassen und Girovernad (DSGV) bank were hit by a 2010 software error, which appears to have affected chip and pin cards.
In Cairns, Australia, Queensland Bank was hit by a Y2K glitch that affected card readers on point of sale machines. According to Cairns.com.au, credit and debit card transactions were being rejected, with "card expired" messages printing on to error receipts dated six years in the future.
In the US, a comment on www.dallas.org noted, "An issue has surfaced on Microsoft Windows Mobile devices, and is reportedly affecting incoming text messages for thousands of users on multiple carriers - most notably Sprint and Verizon." Users on these networks reported receiving text messages with dates set to 2016.
Some IT bloggers said the problems have arisen because programmers in the build up to Y2K did quick fixes which effectively made any two-digit date less than 10 a date in the 2000s, while anything greater than 10 was pushed back into the 1900s.