An anonymous reader writes "Defect in MS OneCare AntiVirus results in Outlook .pst mail folders to be deleted.
This issue has been lingering for some time, and does not seem to be a priority for the vendor.
ref. http://forums.microsoft.com/WindowsOneCare/ShowPos t.aspx?PostID=1150100&SiteID=2 /. MS Bashers will have a good time with this one :-)"