Microsoft has confirmed that there is a problem with the security patch issued in January for its Windows 98 and Windows ME operating systems. Microsoft's KB891711 update has been found to inadequately protect users from a vulnerability related to cursor and icon format handling. The patch was included in security bulletin MS05-002.
"At this point, we have been able to confirm these reports and are currently working on a resolution. Please note that by uninstalling the current update, the machine will return to a vulnerable state." - Jerry Bryant, of Microsoft's Security Response Center.