Deleted and reinstalled printer and duplexing worked.
Linux tarvid-desktop 2.6.32-28-generic #55-Ubuntu SMP Mon Jan 10 21:21:01 UTC 2011 i686 GNU/Linux tarvid@tarvid-desktop:~$ cat /etc/issue Ubuntu 10.04.2 LTS
Deleted and reinstalled printer and duplexing worked.
Linux tarvid-desktop 2.6.32-28-generic #55-Ubuntu SMP Mon Jan 10 21:21:01 UTC 2011 i686 GNU/Linux tarvid- desktop: ~$ cat /etc/issue
tarvid@
Ubuntu 10.04.2 LTS