Are you holding the CTRL key and selecting one cell at a time? Excel is building the
series formula one cell at a time, with a prefix of the sheet name for each cell
address. Instead of your series formula being nice and compact like this:

=SERIES("H",Sheet1!$A$2:$A$10,Sheet1!$H$2:$H$10,2)

it looks like this:

=SERIES(Sheet1!$H$1,(Sheet1!$A$2,Sheet1!$A$3,Sheet 1!$A$4,Sheet1!$A$5,Sheet1!$A$6,Sheet1!$A$7,Sheet1! $A$8,Sheet1!$A$9,Sheet1!$A$10),(Sheet1!$H$2,Sheet1 !$H$3,Sheet1!$H$4,Sheet1!$H$5,Sheet1!$H$6,Sheet1!$ H$7,Sheet1!$H$8,Sheet1!$H$9,Sheet1!$H$10),1)

A series formula has a maximum allowed length of around 1024 characters, but more
limiting is the maximum length of the X values and Y values part of the formula,
which is a shade under 256.

Try to get all your data into a contiguous range so you can reference your ranges
with a single cell reference.

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Peltier Technical Services
Tutorials and Custom Solutions
http://PeltierTech.com/
_______

lschuh wrote:

I have been trying to select the x-axis data labels. It works ok up to a
point then clears out all previous selections. Some of the charts will allow
me to select all the data ranges I want but others don't. Why is this
happening? I have a worksheet with 35 charts on it. Is there some kind of
limit?