It has been verified that AppArmor could  block  access to '.nx/cups' user directory, preventing the possibility of printing with NX.  In this case, the printer appears to be connected successfully and says that the print job printed successfully but the local CUPS never sees the page and no errors are reported.

To solve this issue, you can add the following lines to the '/usr/sbin/cupsd' section of '/etc/apparmor.d/usr.sbin.cupsd' file:

# /etc/init.d/apparmor restart