RadCombox ItemSelected changed to Null When exiting View

I have multiple RadComboBox Inside a
RadGridView. When I open the application, the data is loaded into all
the ComboBox. However, when I get out of the view, the first
ComboBox's itemselected is set to null by itself. If I go back to that
view again, I see the first ComboBox with Null. If I exit again out
of the view, the second ComboBox's itemselected is set to
null. I put an event handler for selectionindexchanged, and it
shows that when I exit the view, selectionindexchanged is triggered and at
the end one of the value that is pulled from a datasource is set to
null. I need to stop the ComboBox from changing the value to null by
itself.