I forgot to mention this link:
It is supposed to bring back the parameters to generate the chart. This is why I guess it is a connection problem due the port number. The error returned by the server is:
"A connection with the server could not be established
/cashmanagementethernuss/DynamicWebCharts/Data/wa_dfc_xmlVB.asp, line 37"
If I go to this page with the server por set as 80, It shows the chart parameters ok.