Exporting the Charts in the non-viewable portion of the Browser:

FusionCharts along with Flash Player, does not allow the charts to render until it is in the viewable area of the browser page.
The exporting of the charts, which are not in the viewable portion of the browser naturally does not take place as the charts are note rendered. This process can only be performed if the page is scrolled down and all the charts in the page are forced to render.

However, there is a work-around to this issue. A "scroll.js" file, when included in the HTML code besides FusionCharts.js, would make the browser scroll till the bottom of the page and then move up to allow all the charts to be rendered.
This would alternately let all the charts be exported when the function is called.

Please check with the attached "scroll.js" file for your reference.