I think there is a need for an FAQ on this. Although the PCL4 Citrix printer emulation is fine for general printer functionality, it doesn't handle niceties like duplex, tray mgmt etc. What you need to do is to actually add/install the driver for the printer on the server and setup the duplex settings on the printer (the printer could be mapped to LPT1 on the server -- it doesn't matter). Also your users need to have the duplex option enabled on their side also. Once they reconnect and auto-create their printer, the duplex setting should be avail to them.