Make sure before you create a control that $('#control_id').data('kendoDropDownList') doesn't exist for a drop down list for instance.
Don't have VS on this computer but something like this might work?
Not sure if the data('...') == undefined will work but this is the general idea - check if the control has data('kendoControlName') set before trying to re-create them.
Maybe this is something the Kendo guys can fix - not try to re-Kendize (just came up with that ;) the control in such cases like yours but a simple check like this should do the trick for you.