Microsoft Corp. quietly deployed a patch to its Windows Live OneCare security suite earlier than expected to fix a bug that has erased some users' e-mail.

"On Sunday, March 11, the Windows Live OneCare team released a new anti-malware engine that will fix the issue of OneCare erroneously quarantining certain Outlook .pst or Outlook Express .dbx files when infected files were detected within them," a Microsoft representative confirmed today. "Windows Live OneCare customers whose PCs are connected to the Internet will automatically get this fix."

Last week, Microsoft responded to user complaints that their Outlook and Outlook Express mail had vanished by acknowledging the bug and naming today as the patch date. As complaints continued to mount, it released the patch ahead of schedule.