In current Ubuntu environments with FreeNX installed, then printing does not work out of the box.
To get it working, we had to change two things:
* Create a symlink for /usr/lib/nx/nxsmb -> /usr/lib/cups/backend
* chmod a+x for /usr/lib/libnxredir.so.0
After this, it's possible to print to the remote printer.
What now is left, is telling gnome/kde to use that local cups server instead of the localhost one.