[Gimp-print-devel] Duplex problem

[Robert H. <rob...@ya...>]

I'm using CUPS+Gutenprint v5.3.3 to print via my Canon Pixma MP970 and its great to be able to use my old buy brilliant printer on my 64-bit iMac. Thank you. However there's no option to print duplex as it used to do when I used a Canon 32-bit driver on my old iMac. Is there a way to make this function again? 
Thanks
Robert