Displaying a "chart" from an Powerpoint-FIle with pptview macro fails

Hi,

when using Office Powerpoint in a Confluence page for example with viewppt macro, the file is not displayed correctly.
If the powerpoint file has a "Chart" sheet in it, it will not displayed.
If downloading the file, its correct, but viewing it in Conflunece with attachment-macro or viewppt it is not possible.