No problems other than the Network going off line occasionally (last night for about an hour). The harware connection failure is a known problem and if you do a serach on the Forum you will be able to read about this. My desktop PC looses the hardware connection regularly, but the laptop has never lost connection. AirNav know that this is a problem and are working on it. Can you try RB on anther PC?
Regarding the Network contacts jumping about, have you tried deselecting the flight path vector which makes the picture look really cluttered. The option is at File/Preferences/Draw 5 minute flight vector path.
These vectors are always going to jump around as they are only a rough estimate of where the aircraft will be in 5 minutes, and as the aircraft turns, this will change by a large amount.
EI-DCF is in Grey so it looks like it has timed out. Once RB is no longer getting information either as a live track or a network track, the aircraft label will go grey and the aircraft will stop moving on the map. The settings you have in File/Preferences/RadarBox/ for Seconds to Timeout and Minutes to Hide will affect this. I find that the default settings are far too long, and I have them set at 30 seconds and 1 minute.
Give this a try and see what you think.