cups printing duplex even when duplex is turned off

[Alfred Monticello]

I'm using Ubuntu 9.10 and CUPS 1.4.1. All of my printers (about 5 of them) are printing double sided, even though under print options I have it disabled under cups. Things printed fine in earlier releases....

Using lp/lpr -o sides=one-sided seems to fix the problem part of the time, but not always.  Anybody have an idea whats causing this?

Could it be a filter setting somewhere?


Thanks..