Is not necessarily a GhostScript problem. I did not find "pnm2ppa: Command not found", but check whether pnm2ppa is installed on your system ("which pnm2ppa"). If not, the problem is that ubuntu-desktop does not require it (then this is a ubuntu-desktop bug).
Another cause for your problem can be in foomatic-gswrapper. To solve it, simply update the foomatic-filters package: sudo apt-get update sudo apt-get install foomatic-filters and check whether you can print then. Then this is a duplicate of bug #23461. ** Changed in: gs-esp (Ubuntu) Status: Confirmed => Needs Info -- Printing on remote Windows shared printer doesn't work https://launchpad.net/bugs/48173 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs