I have installed Nod32 v 2.71.10 on an Windows 2003 SBS server. If I turn XMON (exchange Monitor) on, several mails (not all of them) cannot be opened.An error shows : 'Can't open this item. Unknown Error.' There is no similarity in emails that give this error (html/rtf/txt, with/without attachements) Nod32 reinstallation didnot solve this problem, neither did a downgrade to v 2.71.9. We have installed Nod32 on several similar servers without any problem. I tried changing settings with no change to the result: XMON action changed to no action Background scanning off Detection: advanced heuristics off Anyone a suggestion?