If you recently signed up with Microsoft's OneCare Live antivirus service -- and you use Microsoft Outlook or Outlook Express -- there is a chance that your stored e-mails have been wiped out.
According to user forums on Microsoft's Web site, a year-old bug -- fixed some time last year -- has re-appeared. Apparently, an unknown number of OneCare customers have discovered that their e-mails and calendar entries in Outlook have vanished.
It seems the problem stems from OneCare scanning the Outlook .pst file, discovering that it contained traces of a virus and then either deleting the entire file or moving it into quarantine.
As the .pst file contains all the users' e-mails, the result could be a disaster.
There seems to be confusion as to how many people have been affected by the problem. Some users of the forum have pointed out that because OneCare is designed for home users, many will simply think that their e-mails have gone because of a mistake they made and start again -- without alerting anyone.
Microsoft has already suffered a number of security embarrassments this year. Last month Windows Defender was actually helping virus writers infect a PC; Microsoft also had to patch a 'critical' vulnerability in OneCare that could have allowed a worm to propagate.
Are you a OneCare Live customer? Have you been affected by this problem? Please let us know by using the talkback below or e-mail us at email@example.com.