To reproduce: please refer to the attached sample project and gif file illustrating the behavior. Add cell value in the new row and press teh down arrow.

Workaround: this.radGridView1.MasterTemplate.SelectLastAddedRow = false;

This problem is applicable for OpenEdge as well: http://knowledgebase.progress.com/articles/Article/Telerik-RadGridView-highlights-unnecessary-columns-and-rows-in-batch-mode