There appears to be a problem with the RowHeights.ResizeToFit handling the Orientation properly. We will have to look into it.
As a workaround, you could calculate the string length and use that for the row height. Here is a little snippet.
private void Form1_Load(object sender, System.EventArgs e)
this.gridControl1[1,1].Text = "isdahfkashdfasdfjaskfdjaslkdfjklsjdfkasjdfklsjfkljasldkfj";
this.gridControl1[1,1].WrapText = false;
this.gridControl1[1,1].Font.Orientation = 90;
Graphics g = this.gridControl1.CreateGraphics();
(int) g.MeasureString(this.gridControl1[1,1].Text ,this.gridControl1.Font).Width;
//this.gridControl1.ColWidths = 24;