I'm trying to change a chart in Excel 2003 using VBA. Unfortunately
there's some non-reproducible error that's driving me crazy. I hope
someone here recognizes it.

What I did was to simply record a macro, and go through manually
resetting the chart settings. Then I copied that code to my program and
changed it a bit to have more flexibility. The thing is that it works
perfectly - mostly. Then it will go into stretches of crashing every
time I run it with an error message:

"Run-time error '1004': Unable to set the XValues property of the
Series class"

It does not seem to be my "improvements" to the code which cause the
problem since when my code starts to fail, the original code that the
macro recorder created also fails at the same point. Attached is the
code which runs and/or fails. At the moment it fails at the line marked
with '**** It's frustrating that all the lines above, which are
essentially identical, run ok until it hits the (3).XValues line. Or
sometimes that works and the (4).Values line might fail instead.

Sub MacroRecorderCreated()
ActiveSheet.ChartObjects("Chart 8").Activate
ActiveChart.PlotArea.Select
ActiveChart.SeriesCollection(1).XValues = "=Calc!R6C1:R6000C1"
ActiveChart.SeriesCollection(1).Values = "=Calc!R6C5:R6000C5"
ActiveChart.SeriesCollection(2).XValues = "=Calc!R6C1:R6000C1"
ActiveChart.SeriesCollection(2).Values = "=Calc!R6C8:R6000C8"
ActiveChart.SeriesCollection(3).XValues = "=Calc!R6C1:R6000C1" '****
ActiveChart.SeriesCollection(3).Values = "=Calc!R6C12:R6000C12"
ActiveChart.SeriesCollection(4).XValues = "=Calc!R6C1:R6000C1"
ActiveChart.SeriesCollection(4).Values = "=Calc!R6C11:R6000C11"
ActiveChart.SeriesCollection(5).XValues = "=Calc!R6C1:R6000C1"
ActiveChart.SeriesCollection(5).Values = "=Calc!R6C11:R6000C11"
ActiveWindow.Visible = False
Windows("Stochasitcs2.xls").Activate
Range("J13").Select
End Sub

Does any of this look familiar?

Thanks.

Bill