Comment 33 for bug 416513

I am suffering from the same problem. My Photosmart C6200 series has duplexer installed, but it's not possible to turn it on in "Installable Options", controls are simply not accessible.

It's still possible to use duplexer in openoffice if manually select "Device" → "Duplex" as "Installed" and also select "Paper Size" as A4 Borderless/AutoDuplex. But this way is not useful at all if you need to print many documents, because you'll need to select those options for each document.