How to get RenderGraphCore to be called

Hi,

I am having trouble refreshing the data in my graph. It looks like whenever

graph.Plots[i].Renderer = someRenderer;

or when

graph.Data[i] = someListOfData;

or

graph.Refresh();

is called, the method called RenderGraphCore should be called to rerender the data. My problem is that this is not always true. I am calling graph.Data[i] = someListOfData; twice and the first time I step through the program, it looks like it is getting to RenderGraphCore, the second time, I am modifying the list and then using the same line: graph.Data[i] = someListOfData; and RenderGraphCore is not being called. Is there some explanation of when RenderGraphCore gets fired or why RenderGraphCore isn't being called the second time?

Thanks,
Kelly