I have also confirmed this bug on a Xerox x255, while using the Xerox 133 PPD file. Duplex printing worked in 8.04, but now fails in 8.10. I have all the latest Ubuntu updates including -proposed and -backports. No luck on duplex printing. I am about to try out the fix suggested in this thread to see if it works. Confirming this bug for now as it is definitely a bug.
I have also confirmed this bug on a Xerox x255, while using the Xerox 133 PPD file. Duplex printing worked in 8.04, but now fails in 8.10. I have all the latest Ubuntu updates including -proposed and -backports. No luck on duplex printing. I am about to try out the fix suggested in this thread to see if it works. Confirming this bug for now as it is definitely a bug.