Yes, we do know that we are updating the chart, however the call to setDataURL does not wait for the update to complete before returning control to the calling JavaScript. I don't think it would be a good idea for setDataURL to hold on to control because this would cause everything else to be on hold, so I figured there would be another callback function just like FC_Rendered.
I'm not versed in Flash coding, nor even sure if I have the tools to modify (compile?) the code. In any case, perhaps your modification suggestion might help others who see this post, so please offer up your suggestion.
Thanks.