I'm emailing a project to support@steema.com. If this isn't the right location, let me know. There was one piece of info I left out which is why you couldn't replicate it. If you save the chart to a .tee file, then import it again (which we're doing - it's a web app) you lose the sort on the import ...

This problem was posted on Dec 16 (see original post) but has had no response yet.

When plotting series using FastLine if you mark a plot as null it still draws a line from the Null point to the next valid point not showing a gap in the line. Where as when you switch the SeriesType to csLine there is no line from the NULL point to the next data value. This problem, which is in Tee...

Can you have a Nan in the YArray for Series.Addarray ?
I'm trying to get the equivalent of AddXY and AddNullXY but with better performance