When working with Data views and filters in Sharepoint Designer, the Sharepoint page may some times throw an odd error like
No item exists at http://sitename/pagename.aspx?Id=2.It may have been deleted or renamed by another user.
Typical cause for this issue is that a dataview webpart within the page uses a filter condition that maps ID property of a list to a querystring parameter whose name is ID.
The issue can be easily solved by renaming the querystring parameter to a different name other than ID. After renaming the parameter the Sharepoint page will work as expected.