It has been reported that with an Apple MacBook Air with Mac OS/X 10.5 (Leopard) the NX client may get frequently disconnected from the NX Server.

The issue is probably related to the MacBook Air airport wireless card which is connecting and disconnecting.

If the macbook is connected to the NX server via the built in wireless card, as long as the mouse is moved, the connection never timed out.  As soon as the client side is idle, the connection drops.

A workaround is to open a terminal and run a ping process to e.g. the router IP,
then start the NX session.

At the current state of investigation there is no evidence for a bug in NoMachine NX.