Pivot Charts on the web
 

I recently published a pivot table as a web page and it worked very well. But
when I tried to publish another table (less data) today, it does not work
anymore. The web page was created and all necessay files but the pivot chart
is not working, the values are not displayed in the chart and I am not able
to display them as sums (it always defaults to counts and that can't be
changed).
I can't see any difference in the underlying data (apart from the fact that
there are less)
What can I do?