ClientInstanceName and the public facing HTML id parameter are not the same thing in DevExpress' web forms paradigm, but you can assign the later to the former.

MyGrid.ClientInstanceName = MyGrid.ClientID;

...is an example of doing so in C#. I ran into some nastiness in which an ASPxGridView in an .ascx used several times over in an .aspx staged a scenario wherein the ClientInstanceName when used in JavaScript would affect one grid and not another and not the right thing and there was a bunch of we-are-stepping-on-each-others-toes contamination going on.