I'm not able to print 2-sided to our WorkCentre 7535 when connecting to the printer through our Windows Server 2008 print server. If I connect directly to the printer (i.e., install the print driver on my workstation rather than getting it from the print server) then I am able to print 2-sided. If I print a document from the print server itself, I am also able to print 2-sided. It's just when printing from a workstation that connects to the printer through the print server that I'm unable to print 2-sided.
The settings are exactly the same for both driver installations, as well as the driver versions. What gives?