This may be more of an issue with the Chrome browser, but I suspect there's something about how the underlying PDF is created that is triggering it. We are using the Flex API 3.6 and the GeoEnrichment task to create a summary report for a given geographic area. The request is proxied to ArcGIS Online via our Apache server, using the ESRI-provided proxy code example. The report generates perfectly, and we use the "navigateToURL" option to open the report in a new tab. Again, so far so good.
However, at this point, the browser will not let me save the PDF. This works fine in any flavor of IE or Firefox, it appears to be just Chrome that is the issue. Clicking the "disk" to save just does ... nothing.