I built it from ports.
The server's log is:
-- NX SERVER START: -c /usr/X11R6/NX//bin/nxserver
HELLO NXSERVER - Version 1.4.0-44 OS (GPL)
NX> 105 hello NXCLIENT - Version 1.4.0
NX> 134 Accepted protocol: 1.4.0
NX> 105 SET SHELL_MODE SHELL
NX> 105 SET AUTH_MODE PASSWORD
NX> 105 login
NX> 101 User: marknern
NX> 102 Password:
Info: Auth method: passdb ssh
NX> 103 Welcome to: echo.1fast.us user: marknern
NX> 105 listsession --user="marknern" --status="suspended,running"
--geometry="1024x768x16+render" --type="unix-xdm"
NX> 127 Sessions list of user 'marknern' for reconnect:
Display Type Session ID Options Depth
Screen Status Session Name
------- ---------------- -------------------------------- -------- -----
-------------- ----------- ------------------------------
NX> 148 Server capacity: not reached for user: marknern
NX> 105