OK, I just un-installed ver 4 and downgraded to ver 3.5 as ver 3.5 was working fine for me. I had to install the new ver 4 as I got a new linux box
I get the following error when I try to start the server
[skekkar@rws65223fwks ~/Downloads]$ sudo /usr/NX/bin/nxserver –start
NX> 611 No subscription information found. Please visit the
NX> 611 NoMachine web site at http://www.nomachine.com/
NX> 611 to acquire a valid subscription.
NX> 611 The NX server can’t perform the requested operation.
NX> 999 Bye.