The workaround you have used is the one that I would have suggested as well.
As for the issue, I was not able to reproduce it in a sample application using ScatterLine series.
Would it be possible for you to give us some more information about the exception and how to get it. A sample runnable app with the steps to reproduce it will shed some light and we could manage to reproduce it which will help us in giving you a possible fix. You can either submit a support ticket thread and attach the project there or upload and share it using a third party website for sharing files.
But before that, please ensure this is reproducible with the latest version of our controls as 2013.3 1204 is not the latest one and we did some changes afterwards.
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