No, none of this all.
It has to do with the amount of InSim packets being send out by the server (buttons I think). If it's too much at the same time then something weird happens and it crashes almost all connected clients with this message.
Only Scawen knows whats going on.. But.. Well.. He is on a long tire psychics vacation
It's a really annoying problem though
Maybe helps if the server admin increases TCP memory and buffer pool but you have to know what you are doing or being able to do it at all.
Very busy servers have this problem where a lot of disconnecting/connecting and InSim thingies are running at the same time.
Anyway I am able to reproduce it, if a LFS developer -ever- gets interested.