Sys.WebForms.PageRequestManagerServerErrorException: An entity object cannot be referenced by multiple instances of IEntityChangeTracker

Sys.WebForms.PageRequestManagerServerErrorException: An entity object
cannot be referenced by multiple instances of IEntityChangeTracker

References

Reference NO 1

http://stackoverflow.com/questions/13647165/sys-webforms-pagerequestmanagerservererrorexception-an-entity-object-cannot-be

Reference NO 2

http://www.telerik.com/community/forums/aspnet-ajax/grid/sys-webforms-pagerequestmanagerservererrorexception-an-entity-object-cannot-be-referenced-by-multiple-instances-of-ientitychangetracker.aspx

Reference NO 3

http://social.msdn.microsoft.com/Forums/en-US/147af863-f1e4-4664-8f66-fa1d7bec728d/action?threadDisplayName=syswebformspagerequestmanagerservererrorexception-an-entity-object-cannot-be-referenced-by

Reference NO 4

http://forums.asp.net/p/1587926/4021040.aspx/1?Re+An+entity+object+cannot+be+referenced+by+multiple+instances+of+IEntityChangeTracker+

Reference NO 5

http://www.developpez.net/forums/archive/index.php/f-488.html

Reference NO 6

http://forums.asp.net/p/1587926/4021040.aspx/1?Re+An+entity+object+cannot+be+referenced+by+multiple+instances+of+IEntityChangeTracker+

Reference NO 7

http://answers.flyppdevportal.com/categories/csharp/csharplanguage.aspx

Reference NO 8

http://www.pressingquestion.com/1021870/Syswebformspagerequestmanagerservererrorexception-500