I've noticed a defect in the drawing of the bar element of the RadWaitingBar. It seems that whenever the left side of the bar is not truncated by the left side of the Control, the bar is drawn appropriately, and the control borders are properly visible. However, once the bar reaches the right side of the control and begins to wrap around, it is drawn 'on top' of the left and bottom border of the RadWaitingBar. This makes the control look far less nice. I've noticed this problem in Q1, Q2 and Q3 of telerik 2009.
I've attached two examples. In the bad one, you'll also notice that the colors are being drawn outside of the box in the four corners. In addition, even in the Good one, the four corner pixels are not transparent which would be ideal.