I already answered your support thread and for your convenience and for others who might encounter the same problem I pasted it below:
Thank you for the provided demo, I examined it and I was able to reproduce the problem. It comes from the fact that the RadWindow when used with ContentTemplate databinds its children. This being said, in order to solve the problems please do the following:
1) Remove the explicit call to DataBind() for the combo and the grid - simply leave the datasource as shown below:
RadGrid1.DataSource = list;
RadComboBox1.DataSource = list;
// Insert choose item
2) Move the code which selects the checkbox to the DataBound event of the grid as shown below:
sender, EventArgs e)
(RadGrid1.Items.Count > 0)
//// Select Item B checkbox
I hope that my reply is helpful, let me know how it goes.
the Telerik team
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