Thank you for your answer.
I have downloaded latest version of FusionCharts from our account page and in version.txt I found text
Current Version:FusionCharts XT beta-3 (v3.2.2) (Released on 5th September, 2011)
This is still beta
But when I'm downloading it from http://www.fusioncharts.com/download/
The version text is the follwoing
Current Version:FusionCharts XT (v3.2.2) (Released on 20th September, 2011)
It's too confusing. Could you please tell me how can I download the latest licensed non beta version of FusionCharts 3.2.2
BTW the Invalid argument Error still exists in this version