Mine is a Dual core intel pc 2gb ram.
I have noticed that when I restart the program and track a flight, there appears to be no problem at the beginning. But it happened three times on my PC that, after a couple of minutes, almost all ( not all, about 90% ) network flights disappear from the map (not the grid). After a couple of seconds (5-10) they re-appear again. After this has happened the trouble starts. However this is not always the case. Most of the time the problem starts without the disappearing of the Network flights from the map. So it's a bit hard to trace I guess, but I am not an expert mind you. I just write down what I observe....
Frank