I'm glad that you found your way though the problem.
Another solution I may suggest is using the code you already wrote in the Load method to resize the chart, and then anchoring it. This way the framework will resize the chart for you when needed and you won't need the code in the Resize method.
The code for the Load method is something like:
|radChart1.Size = DockPanel2.Size; |
|radChart1.Anchor = AnchorStyles.Left | AnchorStyles.Top | AnchorStyles.Bottom | AnchorStyles.Right; |
the Telerik team