Is it possible, that dataSource.sync(); causes a double postback if using a slow connection ?
It looks like that the client postback twice if the server doesn't reply within e.g. 15 seconds.
var dataSource = $("#" + gridname).data("kendoGrid").dataSource;
Is it something you have seen before - if not, then I guess I'll have to find it somewhere else in my code :-)
Are there any good ways to prevent double postbacks using the kendo framework?