after having some trouble with RadChart until version 4.x, we just updated from "RadControls for ASP.NET AJAX 2008 1 515" to new "RadControls for ASP.NET AJAX 2008 1 619".
Here is our scenario:
RadChart (IntelligentLabelsEnabled = false -> http://www.telerik.com/community/forums/thread/b311D-begact.aspx#568759
) with 2 ChartSeries of type Bar. ChartSeriesItem-Labels are visible and rotated by -90. In 515 all item labels at least had a small distance (about 5 px or so) to the plotareas border (top, bottom), depending on the length of the label´s text. In 619 all (long text) item labels just end at the border of the plotarea.
So I tried to work with margins and paddings (in 619), but paddings just do the opposite of what I want - in case of specifiing negative values you get funny results, too. Setting margins just had no visible effect. So I tried and tried, getting angry about that and tried to set margins in 515, where it worked as expected - So I think, it´s just a bug.