Thanks Ely,
I was about to respond to my own post with that same property. filterData property filterData:Boolean [read-write] This property is true if the series filters its data before displaying. If a series renders data that contains missing values (such as null, undefined, or NaN), or renders values OUTSIDE THE RANGE OF THE CHART AXES, this property should be set to true (the default). If you know that all of the data in the series is valid, you can set this to false to improve performance One of those d'oh! RTFM moments it seems. But thanks again for the response
