Hello,
I installed Fusion Charts beta on our MOSS site and the web part worked perfectly using a SharePoint list......until we tried to change the chart type from a single series to a multi series. Once I change the chart type I recieved the error message "Invalid XML data". I then tried to change it back to the orginal chart type but still recieved the same error message. The work-around I found is to delete the web part and add it back to your page or hit cancel and find a chart that will work with your data.
It seems Fusion charts is having a problem changing charts types depending on the users data set. My suggestion is when the wizard validates the data rows and column to only display the charts available for that specfic type of data.
