Chart Wizard from a crosstab query? (1 Viewer)

Hi,
Is there any reason why the chart wizard fails with data from a crosstab query?

I did 4 graphs today, the first 3 went like a dream, but the crosstab one fails like this..

It's looking great at the point where you get a sneak preview with a wee button, then next and name it, then finish and hey presto...

undefined function 'format' in expression.

I click ok and it gives me a long blurb about sending too much data, and modifying the source query.
I can't make it any simpler! - there are only 4 fields and 30 or so records.

Any help/advice much apreciated.

Chris.

when i get these types of error's in run the
script in debug to view the exact conflict...I also noticed that within properties, the format has to be set to reflect the type of function that you want.