ExcelBanter - Problems creating dynamic chart in Excel 2007

Hi

I am trying to create a dynamic line chart for my home accounts in Excel
2007 SP1.

I have data entered horizontally by month in a sheet called "Savings".

I have created named ranges as follows:

for the X axis labels:

chtsavings_label=OFFSET(Savings!$C$5,,,1,COUNTA(Sa vings!$C$5:$DQ$5))-1

This is the month title row. The -1 is because the last column is an average
which I do not want to plot

then for each account there is a row with data and I create a named range
like:

chtsavings_acct1_data=OFFSET(chtsavings_label,1,0)

I then try to use these values in the chart via selecting design select data

I try to enter add under "Legend Entries (Series)" e.g.

for "series name" enter "Account 1"

for "Series values" enter =Savings!chtsavings_acct1_data

But when I press the OK button nothing happens. Excel does nothing, no error
message the only option I have is to select the cancel button.

Any ideas where I am going wrong?