[FreeNX-kNX] Fedora 14 - Windows nomachine client tmes out after "negotiating link parameters"

[Stargazer]

Hi list, this is my first post but I've been using the nomachine client 
with Fedora for years.
I have a problem with one Fed 14 server in that after going through all 
the usual authentication stages it always times out with that message. I 
know its not my client because I can connec from home into the office to 
another Fed 14 server, running FreeNX, fine. The setups of both are 
almost identical and I can SSH into both fine from Putty. The server 
with the problem did work until 2 things were changed, but changed in a 
way I'd hoped would have no effect and in fact haven't impacted anything 
else (and so might not be relevant). First, the hosts file was changed - 
it now looks like this, with example.com being replaced with the real 
domain:

127.0.0.1 localhost sabbath.example.com
::1 sabbath localhost6.localdomain6 localhost6

192.168.62.25  zeppelin zeppelin.example.com

Sabbath is the problem machine, Zeppelin is fine. Zeppelin's hosts file 
looks the same with the names and IP's updated. It was changed from the 
default setup because its cron email from addresses were using the 
horrible localhost.localdomain syntax fedora still insists on putting in 
as the default.

The second change, and I think this is different to Zeppelin, is there 
were 3 entries in the network cards list, this is because it was 
initially setup on a hdd in a caddy in another machine, then used in 
Sabbath, hence when the network started it found the local eth device 
and created a new entry. I used networkmanager to point to the eth 
device - in the first config it was using the device but not 
networkmanager. Clearly, that part all works as I can SSH in and in fact 
as I said FreeNX authenticates fine.

These might seem irrelevant but they really are the only things changed 
from a working system. Can anyone spot what I should be looking for to 
fix this please?

Thanks