We just upgraded our server from 2k3 to 2k8 and setup a new print server on 2k8. Initially on roaming profiles every time when user log off they were losing the installed printers. So what I did actually map the printers via 3rd party tool we use called Appsense. When use logs in it already have mapped printers but the problem is two sided printing open is not being saved. Every time user log off /back in gets the same settings.
I have also installed printers manually change the settings but i not remains safe.