ASP.NET 4 GridView EditIndex

"Prior to version 4 of ASP.NET the GridView’s EditIndex property was not automatically set when firing the ‘RowEditing’ event. ASP.NET 4 is now automatically setting the EditIndex property, which is affecting backward compatibility in converted projects. The only way to prevent the grid from now going into edit mode on a row is to set ‘e.Cancel=True’ in the ‘RowEditing’ event"

http://www.craigwardman.com/blog/index.php/2010/10/asp-net-4-gridview-editindex/

http://connect.microsoft.com/VisualStudio/feedback/details/554166/gridview-sets-editindex-property-when-in-previous-net-versions-it-didnt