I am working on a project which was initially developed by someone else. few of my list items are getting updated but i am not getting anything in version history. I believe that some schedule job is updating item.systemupdate(). Does sharepoint store information of item.systemupdate anywhere. I need to know who and when this item was updated (using systemupdate).
As per official Microsoft documentation. The SystemUpdate() method updates your list item without making any changes to Modified or ModifiedBy columns. This would then also conclude that it does not create a new version. From official MS Article : http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.splistitem.systemupdate.aspx