Default chart type crashes vba code upon .add??

I have VBA script that generates charts and works on everyones computer except for one person in our group. The code would crash at the ".add" in the snippet below with the error that I was using wrong parameters for the charttype.

Turns out the way we fixed it was to make her default chart type in her excel settings to be "XYscatter". Although it is working I would like to avoid having to do manual changes to users computers. Why didnt' my code generate the correct type of plot explicity instead of choking on the parameters as iff I was attempting to create a bar chart?

Thanks for any insights :-)

With ActiveSheet.ChartObjects.Add _
        (Left:=chartLeft, Width:=chartWidth, Top:=chartTop, Height:=chartHeight)
         .Chart.SetSourceData Source:=ActiveSheet.Range("a1", "a1")
         .Chart.ChartType = xlXYScatterLines
         .Chart.Parent.Name = newsheetnameis
 End With

Yes, these are managed computers and everyone just got upgraded to office 2007 (haha just in time for 2010).

Originally Posted by Andy Pope

Does this person have the same excel version, include service packs and updates, as the others?

Looks like I might need a plotby in there as well as a chart type?

from http://vbautomation.110mb.com/VBA/charting.htm
Column chart is the default chart type in Excel, and although you can leave out PlotBy:= xlColumns, it is not a good idea because the user may have set his default chart type to a line chart or pie chart, and it doesn’t serve your purpose. SizeWithWindow Property sets MyChart1 to be sized to its window.